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Company Name |
Location |
Area |
Year |
Class |
Box No |
Company No |
| I.R. Refractory Ore Syndicate Ltd | 1905 | BT31 | 11285 | 86316 | ||
| Ibague Mining & Development Co. Ltd | 1909 | BT31 | 18693 | 101251 | ||
| Iberian Mines Syndicate Ltd | Spain | 1892 | BT31 | 5372 | 36909 | |
| Iberian Mining Co | Spain | BT41 | 314 | 1808 | ||
| Iberian Mining Co. Ltd | Spain | 1856 | BT31 | 158 | 476 | |
| Iceland Silica & Mining Syndicate Ltd | Iceland | 1912 | BT31 | 13852 | 120942 | |
| Ida H. Mining Co. Ltd | 1920 | BT31 | 25854 | 166859 | ||
| Idaho Smelting Co. Ltd | 1880 | BT31 | 2604 | 13734 | ||
| Illogan Tin & Copper Mining Co. Ltd | Illogan | Cornwall | 1872 | BT286 | 299 | |
| Ilsington Mining Co. Ltd Vol 1. | Ilsington | Devon | 1907 | BT31 | 34864 | 95444 |
| Imperial Australian Trading Colonizing & Mining Co | BT41 | 316 | 1816 | |||
| Imperial Iron Mining Co. of Lercoul Ltd | 1863 | BT31 | 835 | 710C | ||
| Imperial Mining Co. Ltd | 1867 | BT31 | 1374 | 3798 | ||
| Imperial Ottoman Mining Co. Ltd | Turkey | 1869 | BT31 | 1470 | 4468 | |
| Imperial Silver Lead Copper & Blende Mining Co. Ltd | Wales | 1861 | BT31 | 537 | 2166 | |
| Imuris Mines Ltd | 1889 | BT31 | 4544 | 29761 | ||
| Incorporated Association of Mine Agents of South Staffordshire & East Worcester | Staffordshire | 1867 | BT31 | 1336 | 3513 | |
| Incorporated Diamond Mining Co. Ltd | 1880 | BT31 | 2682 | 14365 | ||
| Incorporated London Chamber of Mines | 1897 | BT31 | 7470 | 53147 | ||
| Indian Mines Agency Ltd | 1893 | BT31 | 5724 | 40035 | ||
| Indian Mines Development Syndicate Ltd | 1903 | BT31 | 10228 | 76749 | ||
| Indian Prospecting Syndicate Ltd | 1896 | BT31 | 6924 | 48712 | ||
| Indian Queens Mining & Colour Co. Ltd | Indian Queens | Cornwall | 1898 | BT31 | 7903 | 56640 |
| Indo-China Smelting Corporation Ltd | 1908 | BT31 | 12563 | 100195 | ||
| Industrial & Mines Syndicate Ltd | 1898 | BT31 | 8166 | 59040 | ||
| Industrial & Mining Consortium Ltd | 1906 | BT31 | 17671 | 87484 | ||
| Industrial Arsenic Co. Ltd | 1908 | BT31 | 12312 | 97127 | ||
| Inglis Syndicate Ltd | 1894-1895 | BT2 | 2668 | |||
| Insu Bippo Mining Co. Ltd | 1910 | BT31 | 19245 | 107700 | ||
| Insu Mining & Development Syndicate Ltd | 1911 | BT31 | 19866 | 114157 | ||
| Insu Mining Co. Ltd | 1910 | BT31 | 19249 | 107718 | ||
| Inter-Continental Mining & Industrial Syndicate Ltd | 1912 | BT31 | 20888 | 123937 | ||
| International Mining Co. Ltd | 1870 | BT31 | 1537 | 4894 | ||
| International Mining Investment & Finance Co.Ltd | 1911 | BT31 | 13552 | 114761 | ||
| International Syndicate for Mining Concessions Ltd | 1911 | BT31 | 13510 | 113956 | ||
| Inveraray Mining Co. Ltd | Inveraray | Argyllshire | 1910 | BT31 | 13295 | 110379 |
| Ione (Nevada) Silver Mines Ltd | Nevada | U.S.A. | 1888 | BT31 | 4115 | 26453 |
| Ipoh Prospecting Syndicate Ltd | 1913 | BT31 | 21531 | 129598 | ||
| Ipu Mining Co. Ltd | 1867 | BT31 | 1371 | 3775 | ||
| Iquique Silver Co. Ltd | Chile | 1888 | BT31 | 4271 | 27702 | |
| Irish Barytes & Umber Company Ltd | Ireland | 1902 | BT31 | 10018 | 74899 | |
| Irish Columnar Basalt Company Ltd | Ireland | 1907 | BT31 | 12109 | 94829 | |
| Irish Copper Mines Ltd | Ireland | 1906 | BT31 | 11585 | 89442 | |
| Irish Exploration & Development Company Ltd | Ireland | 1916 | BT31 | 23478 | 145466 | |
| Irish Granite Co. (Newry) Ltd | Ireland | 1899 | BT31 | 8303 | 60304 | |
| Irish Industrial Minerals Ltd | Ireland | 1910 | BT31 | 13299 | 110438 | |
| Irish Mineral Development Syndicate Ltd | Ireland | 1903 | BT31 | 10162 | 76197 | |
| Irish Mineral Tailings Ltd | Ireland | 1912 | BT31 | 20571 | 121139 | |
| Irish Mines Ltd | Ireland | 1909 | BT31 | 12888 | 104586 | |
| Irish Ochre & Minerals Company Ltd | Ireland | 1910 | BT31 | 13192 | 108889 | |
| Irish Quarries Ltd | Ireland | 1916 | BT31 | 23395 | 144817 | |
| Irish Resources Development Company Ltd | Ireland | 1903 | BT31 | 10285 | 77251 | |
| Irish Zinc-Lead-Silver Mines Ltd | Ireland | 1909 | BT31 | 12687 | 101839 | |
| Iron Mines Syndicate Ltd | 1898 | BT31 | 7934 | 56925 | ||
| Iron Ore Prospecting Syndicate Ltd | 1896 | BT31 | 6763 | 47591 | ||
| Isaac Briggs & Sons Ltd | 1929 | BT31 | 33055 | 237185 | ||
| Isistown Prospecting Co. of Queensland Ltd | 1887 | BT31 | 3869 | 24413 | ||
| Islay Lead Mining Co. Ltd | Islay | Argyllshire | 1872 | BT31 | 1731 | 6362 |
| Isle of Man Antimony Mining Co. Ltd | Isle of Man | 1893 | BT31 | 5701 | 39847 | |
| Isle of Man Mining Co * | Isle of Man | 1856 | BT41 | 324 | 1879 | |
| Italian & Spanish Mining Co. Ltd | 1871 | BT31 | 1663 | 5847 | ||
| Italian Consolidated Mining Co. Ltd | Italy | 1867 | BT31 | 1360 | 3699 | |
| Ivory Coast Consolidated Mines Ltd | 1902 | BT31 | 9771 | 72794 | ||
| J.W. Briggs & Co. Ltd | 1911 | BT31 | 13635 | 116346 | ||
| Jacktrees Mining Co. Ltd | Cleator Moor | Cumberland | 1910 | BT31 | 19743 | 112896 |
| Jagersfontein Central Diamond Mining Co. Ltd | 1913 | BT31 | 14047 | 126463 | ||
| Jalisco (Mexican) Mining Syndicate Ltd | 1906 | BT31 | 17653 | 87263 | ||
| Jamaica Copper Mining Co | Jamaica | 1852 | BT41 | 325 | 1891 | |
| James Briggs & Sons Ltd | 1904 | BT31 | 17338 | 82698 | ||
| James Critchley & Sons Ltd | Batley | Yorkshire | 1903 | BT31 | 16979 | 76560 |
| James Critchley & Sons Ltd | Batley | Yorkshire | 1921 | BT31 | 32501 | 178472 |
| James Dunlop & Co. Ltd | 1886-1901 | BT2 | 1515 | |||
| James McMillan (Mining) Ltd | 1970 | BT2 | 1970 | 788 | ||
| James Nimmo & Co. Ltd | 1893-1936 | BT2 | 2580 | |||
| Jantar (Cornwall) Ltd | Wendron, Porkellis | Cornwall | 1927 | BT31 | 32886 | 226508 |
| Javali Co. Ltd | Nicaragua | 1867 | BT31 | 1379 | 3832 | |
| Jeher Hydraulic Tin Mining Co. Ltd | nd | BT2 | 5938 | |||
| Jemaa (Nigeria) Mining Co. Ltd | 1920 | BT31 | 26272 | 171116 | ||
| Jerusalem Ltd | 1880 | BT31 | 2712 | 14619 | ||
| Johannes Mine Ltd | 1888 | BT31 | 4084 | 26176 | ||
| Johannesburg Mining & General Syndicate Ltd | South Africa | 1895 | BT31 | 6453 | 45483 | |
| Johannissegen Mining Co. Ltd | 1872 | BT31 | 1748 | 6492 | ||
| John Briggs (Gomersal) Ltd | 1906 | BT31 | 11675 | 90322 | ||
| John Naylor & Co. Ltd | 1874 | BT31 | 1967 | 8346 | ||
| John Rhodes Ltd | 1914 | BT31 | 22510 | 137644 | ||
| John Tetlow & Sons Ltd | Todmorden | Yorkshire | 1893 | BT31 | 5724 | 40038 |
| John Watson Ltd | 1890 | BT2 | 2040 | |||
| Johore Rubber & Prospecting Syndicate Ltd | 1905 | BT31 | 11350 | 86929 | ||
| Joseph Briggs & Co. Ltd | 1911 | BT31 | 13590 | 115487 | ||
| Joseph Turner & Sons Ltd | 1900 | BT31 | 9250 | 68698 | ||
| Josephine Mining Co. Ltd | California | U.S.A. | 1887 | BT31 | 4002 | 25458 |
| Jubilee Diamond Mining Syndicate Ltd | 1911 | BT31 | 13559 | 114926 | ||
| Julia Copper Mining Syndicate Ltd | 1908 | BT31 | 12433 | 98574 | ||
| Junction Reefs Mines Co. Ltd | 1887 | BT31 | 4012 | 25533 | ||
| Junction Tin Mine (Nigeria) Ltd | 1923 | BT31 | 32607 | 194197 | ||
| K.D. Tin Mining Syndicate Ltd | 1911 | BT31 | 13744 | 118466 | ||
| Kadur-Mysore Mines Ltd | India | 1901 | BT31 | 9392 | 69752 | |
| Kamerun Mining Co. Ltd | 1913 | BT31 | 21343 | 128079 | ||
| Kamloops Mines (British Columbia) Ltd | 1898 | BT31 | 7903 | 56633 | ||
| Kamloops Mines Ltd | 1904 | BT31 | 10552 | 79748 | ||
| Kangarilla Proprietory Silver Mines (South Australia) Ltd (The) | 1888 | BT31 | 4243 | 27499 | ||
| Kangarilla Silver Mines Ltd | 1892 | BT31 | 5359 | 36780 | ||
| Kansas Mining Co. Ltd | Colorado | U.S.A. | 1871 | BT31 | 1643 | 5673 |
| Kanya Exploration Co. Ltd | South Africa | 1889 | BT31 | 4558 | 29856 | |
| Kapunda Mining Co | Australia | BT41 | 327 | 1904 | ||
| Kapunda Mining Co. Ltd | Australia | 1860 | BT31 | 447 | 1730 | |
| Kassa Mining Co. Ltd | 1919 | BT31 | 32297 | 156755 | ||
| Kehelland Consols Copper Mining Co. Ltd | Camborne | Cornwall | 1874 | BT286 | 359 | |
| Keltie Products Ltd | 1894-1935 | BT2 | 2611 | |||
| Kelynack Tin Mine Ltd | St Just | Cornwall | 1906 | BT31 | 11730 | 90903 |
| Kenmore Mining Co. Ltd | 1910 | BT31 | 13296 | 110381 | ||
| Kerry Creek Mining Co. Ltd | 1911 | BT31 | 20027 | 115928 | ||
| Keswick United Silver Lead Mines Co. Ltd | Crosthwaite | Cumberland | 1872 | BT31 | 1678 | 5966 |
| Ketchau (Pahang) Corporation Ltd | Malaya | 1889 | BT31 | 4344 | 28200 | |
| Keynote Mining Group Ltd | California | U.S.A. | 1889 | BT31 | 4447 | 28961 |
| Kharaskhoma Exploring & Prospecting Syndicate Ltd | 1889 | BT31 | 4371 | 28391 | ||
| Khasia Hills Prospecting & Mining Syndicate Ltd | 1913 | BT31 | 21839 | 132199 | ||
| Kilcrohane & Gurtnakilla Slate & Slab Co. Ltd | Ireland | 1865 | BT31 | 1043 | 1793C | |
| Kilcrohane & Gurtnakilla Slate & Slab Co. Ltd | Ireland | 1864 | BT31 | 1000 | 1552C | |
| Kilkivan Mines (Queensland) Ltd | Queensland | Australia | 1887 | BT31 | 3966 | 25175 |
| Kilkivan Mines Ltd | 1890 | BT31 | 4703 | 31000 | ||
| Killeen Mining Syndicate Ltd | Ireland | 1909 | BT31 | 12637 | 101168 | |
| Killham Associated Tin Mines Ltd | Cornwall | 1906 | BT31 | 11683 | 90409 | |
| Killifreth Mine Ltd | Chacewater | Cornwall | 1896 | BT31 | 15629 | 48379 |
| Killifreth Mine Ltd | Chacewater | Cornwall | 1912 | BT31 | 21009 | 125088 |
| Killin Mining Co. Ltd | 1910 | BT31 | 13296 | 110382 | ||
| Kilmoe Copper Mines Ltd | 1893 | BT31 | 5737 | 40158 | ||
| Kilmorey Lead Mining Co. Ltd | Holywell | Flintshire | 1868 | BT31 | 1395 | 3947 |
| Kilpatrick Mining Co. Ltd | 1910 | BT31 | 13296 | 110383 | ||
| Kilrush Flag Quarry Co. Ltd | Ireland | 1867 | BT31 | 1341 | 3558 | |
| Kilvaughter Iron Mining & Smelting Co. Ltd | 1869 | BT31 | 1462 | 4407 | ||
| Kimberley Mining Co of Du Toits Pan Ltd | 1880 | BT31 | 2685 | 14400 | ||
| Kimberley North Block Diamond Mining Co. Ltd | 1881 | BT31 | 2814 | 15421 | ||
| King Alfred Silver Mining Co. Ltd | 1873 | BT31 | 1879 | 7473 | ||
| King Arthur Silver Lead Mine Ltd | Tintagel | Cornwall | 1870 | BT286 | 195 | |
| King Prempeh Treasure Mines Ltd | 1901 | BT31 | 9550 | 70970 | ||
| King Silver & Copper Mining Co. Ltd | Calstock | Cornwall | 1870 | BT286 | 208 | |
| King’s Down Tin Mine Co. Ltd | St Ewe | Cornwall | 1882 | BT31 | 2981 | 16768 |
| King’s Pocket (Wassaw) Mines Ltd | 1901 | BT31 | 9332 | 69340 | ||
| Kingsdown & Tincroft Mines Ltd | Camborne | Cornwall | 1919 | BT31 | 32308 | 158170 |
| Kingsdown Sett Ltd | St Austell, Hewas Water | Cornwall | 1916 | BT31 | 23416 | 144955 |
| Kingsdown Tin Mining Co, Cornwall Ltd | St Austell, Hewas Water | Cornwall | 1912 | BT31 | 20902 | 124064 |
| Kingside Mines Ltd | Cwmystwyth | Cardiganshire | 1911 | BT31 | 13606 | 115773 |
| Kingside Mining Co. Ltd | Cwmystwyth | Cardiganshire | 1886 | BT31 | 3752 | 23400 |
| Kingside Zinc-Blende Co. Ltd | 1898 | BT31 | 8132 | 58751 | ||
| Kingsley Mining Co. Ltd | 1912 | BT31 | 13816 | 120065 | ||
| Kingsley Mining Co. Ltd | MN | 1895 | BT31 | 6234 | 44183 | |
| Kingston Consols Silver Lead Mining Co. Ltd | Stoke Climsland | Cornwall | 1875 | BT286 | 399 | |
| Kingston United Lead Mining Co. Ltd | Stoke Climsland | Cornwall | 1873 | BT286 | 327 | |
| Kingston Valley Lead Mining Co. Ltd | Stoke Climsland | Cornwall | 1874 | BT286 | 362 | |
| Kingsway Syndicate Ltd | West Harptree | Somerset | 1907 | BT31 | 11848 | 92081 |
| Kirk Michael Mining Co. Ltd | Kirk Michael | Isle of Mam | 1880 | BT31 | 2716 | 14658 |
| Kirkland Prospecting Syndicate Ltd | 1914 | BT31 | 22367 | 136486 | ||
| Kirriemuir Mining Co. Ltd | Angus | 1910 | BT31 | 13296 | 110384 | |
| Kis-Banya Mining Co. Ltd | 1906 | BT31 | 11703 | 90620 | ||
| Kisdon Mining Co. Ltd | Muker | Yorkshire | 1866 | BT31 | 1273 | 3151 |
| Kit Hill Excelsior & East Holmbush Mining Co. Ltd | Stoke Climsland | Cornwall | 1894 | BT31 | 5950 | 41912 |
| Kit Hill Mines Ltd | Callington | Cornwall | 1943 | BT31 | 35770 | 379938 |
| Kit Hill Tunnel Ltd | Calstock | Cornwall | 1877 | BT31 | 2368 | 11687 |
| Kithill Wolfram Mining Co. Ltd | Callington | Cornwall | nd | BT2 | 3435 | |
| Kityia Mines Ltd | 1883 | BT31 | 3144 | 18171 | ||
| Kjoli Mines Ltd | 1903 | BT31 | 10382 | 78181 | ||
| Kledang Tin Mining Co. Ltd | 1906 | BT31 | 11538 | 88957 | ||
| Kledang Tin Mining Co. Ltd | 1910 | BT31 | 32047 | 107609 | ||
| Knightor Treverbyn & Resugga Haematite Iron Ore Mining Co. Ltd | St Austell | Cornwall | 1872 | BT286 | 280 | |
| Knockibae Silver Lead Mining Co. Ltd | New Luce | Wigtownshire | 1870 | BT31 | 1506 | 4693 |
| Knysna Mines Ltd | 1890 | BT31 | 4738 | 31289 | ||
| Kohinoor & Donaldson Consolidated Mining Co. Ltd | Colorado | U.S.A. | 1880 | BT31 | 2720 | 14696 |
| Koley Mines & Exploration Ltd | 1900 | BT31 | 9263 | 68833 | ||
| Kongsberg Consolidated Silver Mines Ltd | Norway | 1884 | BT31 | 3345 | 19908 | |
| Kookorboo Mines Ltd | 1901 | BT31 | 9463 | 70286 | ||
| Kooringa Prospecting Syndicate, Ltd | 1907 | BT31 | 11953 | 93179 | ||
| Kootenay (British Columbia) Smelting & Trading Syndicate Ltd | 1889 | BT31 | 4357 | 28305 | ||
| Kootenay Valleys Co. Ltd | British Columbia | Canada | 1887 | BT31 | 3835 | 24127 |
| Kraszna Forest Land & Mining Co. Ltd | 1913 | BT31 | 14126 | 129695 | ||
| Krautscheid Mining Co. Ltd | BT41 | 338 | 1950 | |||
| Kruisrivier (Whitehead’s) Roodeport & Bloemhof (Transvaal) Estates Co. Ltd | South Africa | 1889 | BT31 | 4356 | 28293 | |
| Kutais Mining & Timber Concessions Ltd | 1906 | BT31 | 17715 | 88138 | ||
| Kwaben Mines Ltd | 1900 | BT31 | 9117 | 67508 | ||
| Kwahu Mining Co. Ltd | 1920 | BT31 | 25944 | 167667 | ||
| Kylon Poton Silver Lead Mining Co. Ltd | Tal-y-bont | Cardiganshire | BT41 | 338 | 1952 | |
| Kylon Potosi Silver Lead Mining Co. Ltd | Tal-y-bont | Cardiganshire | 1858 | BT31 | 362 | 1330 |
| La Fe Mining Co. Ltd | 1911 | BT31 | 20347 | 119059 | ||
| La Gitana Mining Co. Ltd | 1876 | BT31 | 2254 | 10756 | ||
| La Gloria Silver Mines Ltd | Mexico | 1888 | BT31 | 4288 | 27824 | |
| La Inglesita Mines Ltd | 1898 | BT31 | 8179 | 59155 | ||
| La Luz Mines of Mexico Ltd | 1887 | BT31 | 3980 | 25285 | ||
| La Luz Silver Mining Co. Ltd | Mexico | 1868 | BT31 | 1425 | 4158 | |
| La Manche Mining Co. Ltd | 1875 | BT31 | 2157 | 10014 | ||
| La Maria Mine Ltd | 1910 | BT31 | 19587 | 110945 | ||
| La Minera Syndicate, Ltd | 1912 | BT31 | 13796 | 119580 | ||
| La Palma Lead & Silver Mining Co. Ltd | 1907 | BT31 | 12005 | 93703 | ||
| La Paz Mining Co. Ltd | 1906 | BT31 | 17800 | 89264 | ||
| La Plata Mines Ltd | 1890 | BT31 | 4652 | 30583 | ||
| La Plata Mines Ltd | 1892 | BT31 | 5423 | 37422 | ||
| La Plata Mining & Smelting Co. Ltd | 1883 | BT31 | 3167 | 18367 | ||
| La Prata Mine Co. Ltd | Portugal | 1881 | BT31 | 2909 | 16199 | |
| La Reyna Mining Co. Ltd | 1880 | BT31 | 2675 | 14293 | ||
| La Trinidad De Penolas Silver Mine Ltd | 1891 | BT31 | 4971 | 33211 | ||
| La Trinidad Ltd | Mexico | 1884 | BT31 | 3414 | 20507 | |
| La Velera Ltd | Mexico | 1886 | BT31 | 3667 | 22729 | |
| La Victorina Mining Co. Ltd | 1912 | BT31 | 21084 | 125762 | ||
| Lackamore New Mining Co. Ltd | Lackamore | Ireland | 1858 | BT31 | 340 | 1225 |
| Lackamore New Mining Co. Ltd | Lackamore | Ireland | 1857 | BT41 | 339 | 1955 |
| Ladoga Lake Mining & Smelting Co. Ltd | 1908 | BT31 | 12305 | 97038 | ||
| Lady Ann Silver Lead Mining Co. Ltd | Llanarmon | Denbighshire | 1880 | BT31 | 2688 | 14437 |
| Lady Ashburton Silver Mining Co. Ltd | Callington | Cornwall | Not Stated | BT286 | 475 | |
| Lady Ashburton Silver Mining Co. Ltd | Callington | Cornwall | 1879 | BT286 | 474 | |
| Lady Beaconfield Silver Lead Mining Co. Ltd | Holywell | Flintshire | 1874 | BT31 | 1936 | 8049 |
| Lady Bertha United Copper & Tin Mining Co. Ltd | Buckland Monachorum | Devon | 1890 | BT286 | 150 | |
| Lady Bertha United Copper & Tin Mining Co. Ltd | Buckland Monachorum | Devon | 1880 | BT286 | 479 | |
| Lady Constance Lead Mining Co. Ltd | Holywell | Flintshire | 1873 | BT31 | 1888 | 7559 |
| Lady Eliza Lead Mining Co | Llangadog | Carmarthenshire | BT41 | 340 | 1957 | |
| Lady Eliza Lead Mining Co. Ltd | Llangadog | Carmarthenshire | 1859 | BT31 | 419 | 1617 |
| Lady Eliza Mining Co. Ltd | Llangadog | Carmarthenshire | 1857 | BT31 | 312 | 1083 |
| Lady Franklin Mining Co. Ltd | New Mexico | U.S.A. | 1886 | BT31 | 3755 | 23411 |
| Lady Loch Mines Ltd | 1902 | BT31 | 9951 | 74242 | ||
| Lady Rashleigh Consols Mine Ltd | Luxulyan | Cornwall | 1888 | BT286 | 590 | |
| Lady Rashleigh Consols Mine Ltd | Luxulyan | Cornwall | 1888 | BT286 | 116 | |
| Ladywell Mine Co. Ltd | Shelve | Shropshire | 1898 | BT31 | 8222 | 59588 |
| Ladywell Mining Co. Ltd | Shelve | Shropshire | 1873 | BT31 | 1837 | 7169 |
| Laguna Silver Mining Co. Ltd | Mexico | 1862 | BT31 | 639 | 2684 | |
| Lagunazo Sulphur & Copper Co. Ltd | Spain | 1860 | BT31 | 481 | 1880 | |
| Lainglesa Mines Ltd | 1896 | BT31 | 7066 | 49772 | ||
| Lake District Hamaetite & Mining Co. Ltd | Cumberland | 1873 | BT31 | 1891 | 7588 | |
| Lake George (North) Mines Ltd | 1899 | BT31 | 8667 | 63227 | ||
| Lake George Mines Ltd | 1901 | BT31 | 9489 | 70495 | ||
| Lake George Mines Ltd | 1896 | BT31 | 7047 | 49642 | ||
| Lake George Mining Corporation Ltd F Vol. | 1937 | BT31 | 41466 | 325131 | ||
| Lake George Mining Corporation Ltd Vol 2 | 1937 | BT31 | 41467 | 325131 | ||
| Lake Superior Copper Co. Ltd | 1885 | BT31 | 3472 | 21028 | ||
| Lake Superior Mining Co. Ltd | 1889 | BT31 | 4458 | 29057 | ||
| Lake Superior Native Copper Co. Ltd | Ontario | Canada | 1881 | BT31 | 2761 | 15039 |
| Lake Superior Queen Silver Ltd | Ontario | Canada | 1890 | BT31 | 4750 | 31378 |
| Lakes Mines Co. Ltd | Cumberland | 1893 | BT31 | 5510 | 38200 | |
| Lambert Mining Co. Ltd | 1875 | BT286 | 400 | |||
| Lamplugh Hematite Iron Mining Co. Ltd | Lamplugh | Cumberland | 1872 | BT31 | 1726 | 6319 |
| Lanark Oil Co. Ltd | Lanarkshire | 1883-1890 | BT2 | 1267 | ||
| Lancashire & Yorkshire Cotton Manufacturing & Mining Co. Ltd | 1860 | BT31 | 494 | 1953 | ||
| Lancashire & Yorkshire Cotton Manufacturing & Mining Co. Ltd | BT41 | 344 | 1973 | |||
| Lancelot Freehold Tin & Copper Mines Ltd | 1903 | BT31 | 10312 | 77524 | ||
| Land & Mining Rights Co. Ltd | 1912 | BT31 | 13988 | 124514 | ||
| Lander City Silver Mining Co. Ltd | Nevada | U.S.A. | 1865 | BT31 | 1121 | 2240C |
| Laneast & Egloskerry Manganese Mines Ltd | Egloskerry | Cornwall | 1885 | BT286 | 561 | |
| Laneast & Egloskerry Manganese Mines Ltd | Egloskerry | Cornwall | 1885 | BT286 | 38 | |
| Lanerth Mining Co. Ltd | 1919 | BT31 | 24659 | 155507 | ||
| Lanestosa Lead & Zinc Mining Co. Ltd | Spain | 1871 | BT31 | 1640 | 5649 | |
| Langford Manganese Co. Ltd | Newton St Cyres | Devon | 1888 | BT31 | 4173 | 26971 |
| Langford Silver & Copper Mining Co. Ltd | Callington | Cornwall | 1881 | BT31 | 2886 | 15987 |
| Langness Copper Co. Ltd | Malew | Isle of Man | 1891 | BT31 | 5018 | 33637 |
| Langsaun Tin Mining Co. Ltd | nd | BT2 | 5805 | |||
| Langstone Manganese Mine Co. Ltd | Lamerton | Devon | 1880 | BT286 | 505 | |
| Lanivet Mining Co. Ltd | Lanivet | Cornwall | 1864 | BT286 | 51 | |
| Larne Iron Mines Ltd | Ireland | 1877 | BT31 | 2376 | 11764 | |
| Larne Salt & Alkali Co. Ltd | Ireland | 1907 | BT31 | 18274 | 95710 | |
| Las Animas Copper Mining & Smelting Co. Ltd | 1902 | BT31 | 9716 | 72366 | ||
| Las Cabesses Manganese Mines Ltd | 1894 | BT31 | 5770 | 40434 | ||
| Las Caldas Freehold Malachite Copper Mining Co. Ltd | 1880 | BT31 | 2717 | 14675 | ||
| Las Infantas Lead Mining Co | Linares | Spain | 1853 | BT41 | 345 | 1989 |
| Las Rozas Mines Ltd | 1897 | BT31 | 7460 | 53032 | ||
| Last Chance Consolidated Silver Mining Co. Ltd | Utah | U.S.A. | 1880 | BT31 | 2694 | 14494 |
| Last Chance Silver Mining Co of Utah Ltd | Utah | U.S.A. | 1872 | BT31 | 1714 | 6217 |
| Laurentian Mining Ltd | 1923 | BT31 | 27949 | 190505 | ||
| Laxey Neath Smelting Co. Ltd | 1867 | BT31 | 1369 | 3762 | ||
| Lead Era Mining Co. Ltd | Llandigla | Flintshire | 1878 | BT31 | 2458 | 12539 |
| Lead Hills Mining Co. | Leadhills | Lanarkshire | 1868-1893 | BT2 | 278 | |
| Lead Mines of Tibet Ltd | Tibet | 1904 | BT31 | 10758 | 81545 | |
| Lead Mines of Wales Ltd | Wales | 1920 | BT31 | 25722 | 165460 | |
| Lead Mines Syndicates Ltd | Wales | 1889 | BT31 | 4383 | 28478 | |
| Lead Warrant Co. Ltd | MN | 1883 | BT31 | 3097 | 17739 | |
| Leadhills Co. Ltd | Leadhills | Lanarkshire | 1903 | BT31 | 17105 | 78640 |
| Leadhills Silver Lead Mining & Smelting Co. Ltd | Leadhills | Lanarkshire | 1876 | BT31 | 2271 | 10886 |
| Leadville Mines Ltd | Colorado | U.S.A. | 1888 | BT31 | 4140 | 26699 |
| Leeds Rock House Lead Mining Co. Ltd | Shelve | Shropshire | 1868 | BT31 | 1421 | 4126 |
| Leeswood Smelting Co. Ltd | Leeswood | Flintshire | 1887 | BT31 | 3835 | 24126 |
| Leeswood Spelter Co. Ltd | Leeswood | Flintshire | 1890 | BT31 | 4681 | 30821 |
| Leicester Diamond Mines Ltd | 1898 | BT31 | 8238 | 59769 | ||
| Leicestershire Ironstone & Smelting Co. Ltd | Leicestershire | 1871 | BT31 | 1662 | 5840 | |
| Lelant Mining Co. Ltd | Lelant | Cornwall | 1905 | BT31 | 11135 | 84885 |
| Leon Cobalt & Copper Mining Co. Ltd | Spain | 1890 | BT31 | 4755 | 31425 | |
| Leopold Hutte Iron Mining & Smelting Co. Ltd | 1873 | BT31 | 1819 | 7033 | ||
| Leopold Von Buch Consolidated Mining Co. Ltd | 1873 | BT31 | 1815 | 6997 | ||
| Lerida Copper Mines Ltd | 1899 | BT31 | 8457 | 61549 | ||
| Lerry Mines Co. Ltd | Tal-y-bont | Cardiganshire | 1861 | BT31 | 572 | 2356 |
| Lery Mining Co. Ltd | 1909 | BT31 | 18915 | 103812 | ||
| Les Grandes Mines Consoliders De Villernagne Ltd | 1863 | BT31 | 806 | 557C | ||
| Les Mines De Cuivre D’aker Ltd | 1897 | BT31 | 7538 | 53701 | ||
| Les Mines De Cuivre De La Fare Ltd | 1895 | BT31 | 6500 | 45757 | ||
| Les Mines De Cuivre Pilou Ltd | 1899 | BT31 | 8715 | 63687 | ||
| Levant Mineral Co. Ltd | Turkey | 1857 | BT31 | 246 | 804 | |
| Levant Tin Mines Ltd | St Just | Cornwall | 1920 | BT31 | 32383 | 164080 |
| Liang Tin Lands Limited | 1899 | BT31 | 8455 | 61530 | ||
| Liberty Mining Co. Ltd | Virginia | U.S.A. | 1852 | BT41 | 356 | 2033 |
| Liberty Mining Co. Ltd | 1858 | BT31 | 329 | 1170 | ||
| Libiola Copper Mining Co. Ltd | 1867 | BT31 | 1322 | 3439 | ||
| Lightning Mine Trust Ltd | 1929 | BT31 | 33141 | 244250 | ||
| Liguanea & General Mining Co. Liguanea & General Mining Co. of Jamaica | BT41 | 360 | 2046 | |||
| Lillooet (British Columbia) Mining Co, Ltd | 1914 | BT31 | 32175 | 133706 | ||
| Linares Lead Mining Co | Linares | Spain | 1858 | BT41 | 361 | 2049 |
| Linares Lead Mining Co. Ltd | Linares | Spain | 1906 | BT31 | 17812 | 89389 |
| Linares Lead Mining Co. Ltd | Linares | Spain | 1863 | BT31 | 858 | 816C |
| Linares Zinc Mining Co. Ltd | Linares | Spain | 1876-1881 | BT2 | 691 | |
| Lincolnshire Iron Smelting Co. Ltd | Lincolnshire | 1872 | BT31 | 1724 | 6314 | |
| Linden Lead Mining & Smelting Co. Ltd | 1860 | BT31 | 519 | 2075 | ||
| Lindsay’s Consolidated Mines Ltd | 1896 | BT31 | 6970 | 49065 | ||
| Linthorpe-Dinsdale Smelting Co. Ltd | 1903 | BT31 | 16997 | 76930 | ||
| Lion’s Den Tin Mine Syndicate Ltd | 1895-1896 | BT2 | 2859 | |||
| Lisburn Consols Ltd | Pont-ar-llechau | Cardiganshire | 1865 | BT31 | 1144 | 2376C |
| Lisburne Consols Silver Lead Mining Co. Ltd | Yspytty | Cardiganshire | 1868 | BT31 | 1412 | 4070 |
| Lisburne Development Syndicate Ltd | Pontrhydygroes | Cardiganshire | 1907 | BT31 | 18031 | 92551 |
| Lisburne Mines (New Lease) Co. Ltd | Pontrhydygroes | Cardiganshire | 1896 | BT31 | 6851 | 48198 |
| Lisburne Mines Co. Ltd | Pontrhydygroes | Cardiganshire | 1864 | BT31 | 981 | 1439C |
| Liscannor Quarry Co. Ltd | Caherbarnagh | Ireland | 1891 | BT31 | 5164 | 34895 |
| Liscannor Quarry Company (1905) Ltd | Caherbarnagh | Ireland | 1905 | BT31 | 11329 | 86741 |
| Lisheranig Silver Mining Co. Ltd | Ireland | 1881 | BT31 | 2787 | 15221 | |
| Little Down & Ebber Rocks Mineral & Mining Co. Ltd | Wookey | Somerset | 1858 | BT41 | 364 | 2068 |
| Little Down & Ebber Rocks Mineral & Mining Co. Ltd | Wookey | Somerset | 1858 | BT31 | 373 | 1375 |
| Little Down & Ebber Rocks Mineral Mining Co. Ltd | Wookey | Somerset | 1856 | BT31 | 199 | 601 |
| Little Josephine (Colorado) Mining Co. Ltd | Colorado | U.S.A. | 1888 | BT31 | 4051 | 25882 |
| Little Josephine (Colorado) Mining Co. Ltd | Colorado | U.S.A. | 1891 | BT31 | 4956 | 33101 |
| Little Wonder Mineral Co. Ltd | Flintshire | 1877 | BT31 | 2349 | 11508 | |
| Liverpool Barytes Company Ltd | Ireland | 1907 | BT31 | 18204 | 94831 | |
| Liverpool Manganese Co. Ltd | Ireland | 1907 | BT31 | 18285 | 95837 | |
| Lixa Mining Co. Ltd | Portugal | 1887 | BT31 | 14887 | 25211 | |
| Llan Gan Lead Mining Co. Ltd | Langan | Glamorganshire | 1876 | BT31 | 2248 | 10716 |
| Llanarmon District Mines Drainage Co. Ltd | Llanarmon-yn-Ial | Denbighshire | BT31 | 44588 | 1045030 | |
| Llanarmon Lead Mining Co. Ltd | Llanarmon | Denbighshire | 1869 | BT31 | 1482 | 4531 |
| Llanbadarnfawr Lead Mine Co. Ltd | Llanbadarnfawr | Cardiganshire | 1879 | BT31 | 2548 | 13260 |
| Llanberis Copper Mining Co. Ltd | Llanberis | Caernarvonshire | 1873 | BT31 | 1858 | 7315 |
| Llanddewibrefe United Silver Lead Mining Co. Ltd | Llanddewi Brefi | Cardiganshire | 1856 | BT41 | 375 | 2113 |
| Llandegla Mining Co. Ltd | Llanarmon-yn-Ial | Denbighshire | 1879 | BT31 | 2488 | 12783 |
| Llandilo Lead Zinc & Copper Mining & Smelting Co. Ltd | Llandeilo | Carmarthenshire | BT41 | 375 | 2114 | |
| Llandilo Lead Zinc & Copper Mining & Smelting Co. Ltd | Llandeilo | Carmarthenshire | 1857 | BT31 | 226 | 720 |
| Llandilo Mining Co. Ltd | Llandilo | Carmarthenshire | 1873 | BT31 | 1856 | 7303 |
| Llanelltyd Silver Lead Mining Co. Ltd | Llanelltyd | Merionethshire | 1873 | BT31 | 1826 | 7088 |
| Llanerch y Baidd Mining Co. Ltd | Wales | BT41 | 375 | 2118 | ||
| Llanerch y Baidd Mining Co. Ltd | Wales | 1860 | BT31 | 492 | 1942 | |
| Llanfair Mines Co. Ltd | Lampeter | Cardiganshire | 1860 | BT31 | 470 | 1823 |
| Llanfair Mines Co. Ltd | Llanfair Talhaiarn | Denbighshire | BT41 | 375 | 2119 | |
| Llanfair Mines Ltd | Llanfair Talhaiarn | Denbighshire | 1900 | BT31 | 9065 | 67072 |
| Llanfair Mining Co. Ltd | Llanfair Talhaiarn | Denbighshire | 1890 | BT31 | 4875 | 32380 |
| Llanfyrnach Silver Lead Mining Co. Ltd | Llanfyrnach | Pembrokeshire | 1858 | BT31 | 349 | 1265 |
| Llanfyrnach Silver Lead Mining Co. Ltd | Llanfyrnach | Pembrokeshire | BT41 | 376 | 2121 | |
| Llangan Lead Mining Co. Ltd | Cowbridge | Pembrokeshire | 1862 | BT31 | 665 | 2815 |
| Llangynog United Mining Co. Ltd * | Llanrhaeadr | Montgomeryshire | 1856 | BT41 | 376 | 2126 |
| Llanidloes Lead Mining Co. Ltd | Llanidloes | Montgomeryshire | 1874 | BT31 | 2048 | 8960 |
| Llanidloes Mining & Machinery Co. Ltd | Llanidloes | Montgomeryshire | 1908 | BT31 | 18579 | 99955 |
| Llanidloes Wheal Van Lead Mining Co. Ltd | Llanidloes | Montgomeryshire | 1870 | BT31 | 1523 | 4798 |
| Llanrhaiadr Lead Mining Co. Ltd | Llanrhaeadr | Montgomeryshire | 1875 | BT31 | 2073 | 9186 |
| Llanrwst Consolidated Mines Ltd | Llanrwst | Caernarvonshire | 1908 | BT31 | 31998 | 98491 |
| Llanrwst Lead Mining Co. Ltd | Llanrwst | Caernarvonshire | 1873 | BT31 | 1893 | 7614 |
| Llansamlet Smelting Co. Ltd | Llansamlet | Glamorganshire | 1882 | BT31 | 3033 | 17181 |
| Llansawel Lead Mining Co. Ltd | Llansawel | Carmarthenshire | 1879 | BT31 | 2480 | 12721 |
| Llo Nickel Mining Co. Ltd | 1867 | BT31 | 1338 | 3522 | ||
| Llwynenion Mining Syndicate Ltd | 1893 | BT31 | 5691 | 39768 | ||
| Llwynmalees Mine Co. Ltd | Ystradmeurig | Cardiganshire | 1856 | BT31 | 3 | 22 |
| Llwynmalees Mine Co. Ltd | Ystradmeurig | Cardiganshire | BT41 | 377 | 2132 | |
| Llwynmalees Silver & Lead Mining Co. Ltd | Ystradmeurig | Cardiganshire | 1865 | BT31 | 1178 | 2568C |
| Llwynmalees Silver Lead Mining Co. Ltd | 1865 | BT31 | 1178 | 2568C | ||
| Llwynteify Lead Mining Co. Ltd | Cardiganshire | 1873 | BT31 | 1880 | 7483 | |
| Llyn y Pandy Lead Mining Co. Ltd | Gwernaffield | Flintshire | 1872 | BT31 | 1744 | 6452 |
| Llynclys United Lead Copper & Oxide Mining Co. Ltd | Oswestry | Shropshire | 1873 | BT31 | 1895 | 7631 |
| Llyny Pandy Mining Co. Ltd | Gwernaffield | Flintshire | 1912 | BT31 | 21111 | 126038 |
| Llywernog Co. Ltd | Ponterwyd | Cardiganshire | 1868 | BT31 | 1434 | 4212 |
| Llywernog Co. Ltd | Ponterwyd | Cardiganshire | 1872 | BT31 | 1710 | 6192 |
| Llywernog Co. Ltd | Ponterwyd | Cardiganshire | 1861 | BT31 | 586 | 2433 |
| Llywernog United Mining Co. Ltd | Llywernog | Cardiganshire | 1858 | BT31 | 348 | 1259 |
| Llywernog United Mining Co. Ltd | Llywernog | Cardiganshire | BT41 | 377 | 2131 | |
| Loch Mines Ltd | 1905 | BT31 | 11252 | 85973 | ||
| Lochwinnoch Consols Copper Mining Co. Ltd | Lochwinnock | Scotland | 1861-1881 | BT2 | 66 | |
| Lolita & Mejora Mines Ltd | 1883 | BT31 | 3257 | 19140 | ||
| Lomagundie Exploration Co. Ltd | 1896-1900 | BT2 | 3181 | |||
| Lomah (Rhodesia) Mining Co. Ltd Vols 1 & 2. | 1924 | BT31 | 35326 | 198357 | ||
| Lomax Silver Lead Mining Co. Ltd | Sithney | Cornwall | 1880 | BT286 | 496 | |
| London & California Mining Co. Ltd | 1872 | BT31 | 1679 | 5969 | ||
| London & Jagersfontein Diamond Mining Co. Ltd | 1881 | BT31 | 2789 | 15243 | ||
| London & Limpopo Mining Co. Ltd | 1868 | BT31 | 1429 | 4184 | ||
| London & Mount Lyell Prospecting Co. Ltd | 1896 | BT31 | 15600 | 47611 | ||
| London & Silverton Mining Co. Ltd | 1882 | BT31 | 3091 | 17699 | ||
| London & South African Prospecting & Land Syndicate Ltd | 1887 | BT31 | 3879 | 24479 | ||
| London & Westralian Mines & Finance Agency Ltd | 1900 | BT31 | 8820 | 64713 | ||
| London & Westralian Mines & Finance Agency Ltd | 1895 | BT31 | 6419 | 45319 | ||
| London African Prospecting Co. Ltd | 1887 | BT31 | 3818 | 23960 | ||
| London Association & Register of Shareholders in Colonial & Foreign Mines Ltd | 1893 | BT31 | 5658 | 39484 | ||
| London Bembesi Prospecting Syndicate Ltd | 1912 | BT31 | 13964 | 123865 | ||
| London Cosmopolitan Mining Co. Ltd | 1907 | BT31 | 31982 | 95957 | ||
| London Lead Smelting Co. Ltd | 1896 | BT31 | 7162 | 50565 | ||
| London Mines Finance Co. Ltd | 1902 | BT31 | 9846 | 73387 | ||
| London Mining Trust Ltd | 1906 | BT31 | 11753 | 91129 | ||
| London Prospecting Co. Ltd | 1896 | BT31 | 6967 | 49053 | ||
| London Smelting Co. Ltd | Penryn | Cornwall | 1921 | BT31 | 32490 | 176348 |
| London Smelting Works Ltd | 1892 | BT31 | 5450 | 37679 | ||
| London Tin Smelting Co. Ltd | 1915 | BT31 | 32214 | 141573 | ||
| Londonderry Consols Ltd | 1895-1899 | BT2 | 2886 | |||
| London-Mexican Prospecting & Finance Co. Ltd | 1887 | BT31 | 3872 | 24432 | ||
| Long Rake Lead & Spar Mining Co. Ltd | Youlgreave | Derbyshire | 1881 | BT31 | 2811 | 15397 |
| Lonsdale Hematite Iron & Steel Co. Ltd | Ennerdale | Cumberland | 1896 | BT31 | 6897 | 48512 |
| Lonsdale Hematite Iron & Steel Co. Ltd | Ennerdale | Cumberland | 1883 | BT31 | 3194 | 18567 |
| Lonsdale Hematite Smelting Co. Ltd | Ennerdale | Cumberland | 1897 | BT31 | 7473 | 53180 |
| Lonsdale Lead Mining Co. Ltd | Westmorland | 1874 | BT31 | 2017 | 8718 | |
| Lonsdale Vale Iron Co. Ltd | Kildale | Yorkshire | 1865 | BT31 | 1109 | 2166C |
| Lord Byron & Valentine Mining Co. Ltd | Cornwall | 1881 | BT31 | 2829 | 15539 | |
| Lord Kimberley Mine Exploration Co. Ltd | 1880 | BT31 | 2724 | 14730 | ||
| Lord Kimberley Mine Falmouth Ltd | Falmouth | Cornwall | 1881 | BT31 | 2881 | 15939 |
| Lossiemouth Lead Mining Co. Ltd | Lossiemouth | Scotland | 1878 | BT31 | 2419 | 12169 |
| Loughtea Slate Quarry Co. Ltd | Ireland | 1857 | BT41 | 409 | 2334 | |
| Loughtea Slate Quarry Co. Ltd | Ireland | 1857 | BT31 | 245 | 799 | |
| Loveden Mine Ltd | Tal-y-bont | Cardiganshire | 1900 | BT31 | 9189 | 68151 |
| Low Moor Co. | Bradford | Yorkshire | 1867 | BT31 | 1348 | 3623 |
| Low Moor Iron Co. Ltd | Bradford | Yorkshire | 1929 | BT31 | 33088 | 239705 |
| Lower Park Mining Co. Ltd | Esclusham Above | Denbighshire | BT41 | 410 | 2336 | |
| Lower Park Mining Co. Ltd | Wrexham | Denbighshire | 1860 | BT31 | 455 | 1758 |
| Lower Van & Nantiago Mines Ltd | Llanidloes | Montgomeryshire | 1878 | BT31 | 2442 | 12394 |
| Lower Weardale Minerals Co. Ltd | Weardale | Durham | 1888 | BT31 | 4101 | 26309 |
| Loweswater Lead Co. Ltd | Loweswater | Cumberland | 1887 | BT31 | 4012 | 25536 |
| Lucky Tiger Mining Syndicate Ltd | 1910 | BT31 | 13412 | 112225 | ||
| Ludwell Mining Co. Ltd | MN | 1863 | BT31 | 777 | 413C | |
| Luisa Iron Mining Co. Ltd | 1874 | BT31 | 1951 | 8205 | ||
| Lusitanian Mining Co | Aljustrel | Portugal | BT41 | 411 | 2343 | |
| Lusitanian Mining Co. Ltd | Aljustrel | Portugal | 1856 | BT31 | 35 | 161 |
| Luxulian Iron Mines Ltd | Luxulyan | Cornwall | 1872 | BT286 | 307 | |
| Luxulyan Consols Ltd | Luxulyan | Cornwall | 1888 | BT31 | 4150 | 26784 |
| Luxulyan Tin Mine Co | Luxulyan | Cornwall | 1881 | BT31 | 2895 | 16070 |
| Lydenburg Consolidated Mines Ltd | 1895 | BT31 | 6379 | 45051 | ||
| M. Briggs & Son Ltd | 1906 | BT31 | 11766 | 91249 | ||
| M.C. Mining Co. of British Columbia Ltd | 1923 | BT31 | 27863 | 189437 | ||
| Macclesfield Patent Sulphate of Copper Co. | Macclesfield | Cheshire | 1862 | BT31 | 716 | 104C |
| Macedonian Exploration & Mining Syndicate Ltd | 1910 | BT31 | 19286 | 108039 | ||
| Machynlleth Park Copper Mine Co. Ltd | Machynlleth | Montgomeryshire | 1856 | BT31 | 103 | 355 |
| Machynlleth Park Copper Mine Co. Ltd | Machynlleth | Montgomeryshire | BT41 | 413 | 2351 | |
| Mackay & Revolution Silver Mining Co. Ltd | Utah | U.S.A. | 1883 | BT31 | 3171 | 18401 |
| Maes y Safn Mine Co. Ltd | Llanferres | Denbighshire | 1862 | BT31 | 663 | 2800 |
| Magdalen Mine Ltd | Ponsonooth | Cornwall | 1924 | BT31 | 28738 | 200968 |
| Maggi Foundry & Smelting Co. Ltd | 1917 | BT31 | 23554 | 146059 | ||
| Magnet Princess Mines Ltd | 1896 | BT31 | 7082 | 49902 | ||
| Magnetic Iron Mountain Smelting Co. Ltd | 1888 | BT31 | 4066 | 25990 | ||
| Magpie & True Blue Mining Co. Ltd | Holywell | Flintshire | 1913 | BT31 | 21784 | 131761 |
| Maid of Erin Silver Mines Ltd | Colorado, Leadville | U.S.A. | 1891 | BT31 | 5063 | 34033 |
| Mailele Mining Co. Ltd | 1935 | BT31 | 33602 | 301721 | ||
| Malacate Mining & Smelting Co. Ltd | 1895 | BT31 | 6561 | 46176 | ||
| Malaga Lead Co. Ltd | Spain | 1871 | BT31 | 1652 | 5758 | |
| Malaga Mining & Trading Syndicate Ltd | Spain | 1907 | BT31 | 11981 | 93491 | |
| Malay Prospecting Syndicate Ltd | Malaya | 1910 | BT31 | 13157 | 108483 | |
| Malay States Prospecting Syndicate Ltd | Malaya | 1903 | BT31 | 10252 | 76997 | |
| Malay States Tin Mines Ltd | Malaya | 1889 | BT31 | 4476 | 29216 | |
| Malay States Tin Mines Ltd | Malaya | 1896 | BT31 | 6640 | 46700 | |
| Malayan Peninsula (East India) Tin Mining Co. Ltd | Malaya | 1874 | BT31 | 1990 | 8538 | |
| Malcolm Mines Ltd | 1902 | BT31 | 10130 | 75905 | ||
| Malew Silica Reef Co. Ltd | Malew | Isle of Man | 1887 | BT31 | 3804 | 23834 |
| Malpas Stone Quarrying Co. Ltd | Ireland | 1912 | BT31 | 13909 | 122384 | |
| Mame Mining Syndicate Ltd | 1906 | BT31 | 11683 | 90425 | ||
| Mammoth Copperopolis of Utah Ltd | Utah | U.S.A. | 1871 | BT31 | 1666 | 5880 |
| Manchegan Mines Ltd | Spain | 1905 | BT31 | 11305 | 86486 | |
| Manchuria Mining Syndicate Ltd | China | 1906 | BT31 | 17776 | 88988 | |
| Manghold Head Mining Co. Ltd | Maughold | Isle of Man | 1872 | BT31 | 1798 | 6862 |
| Manica Ophir Mining Co. Ltd | Mozambique | 1889 | BT31 | 4375 | 28429 | |
| Manitoba Mortgage & Investment Co. Ltd | Manitoba | Canada | 1880 | BT31 | 14664 | 14736 |
| Manitoba Mortgage & Investment Co. Ltd | Manitoba | Canada | 1906 | BT31 | 31946 | 89624 |
| Mansfield Mexican Silver Mines Ltd | 1887 | BT31 | 3948 | 25029 | ||
| Manta Mining Co. Ltd | 1909 | BT31 | 32021 | 103424 | ||
| Manter Mining Co. Ltd | 1874 | BT31 | 2017 | 8723 | ||
| Mantezuma Silver Lead Mines (Colorado) Ltd | 1917 | BT31 | 23719 | 147610 | ||
| Manx Silver Lead Mineral Co. Ltd | Onchan | Isle of Man | 1875 | BT31 | 2093 | 9402 |
| Marazion Mines Ltd | Marazion | Cornwall | 1907 | BT31 | 12151 | 95331 |
| Marcia Hematite Iron Mining Co. Ltd | 1873 | BT286 | 353 | |||
| Mareeba Amtimony Mine Ltd | 1900 | BT31 | 8843 | 64955 | ||
| Marganai Forest & Mining Co. Ltd | 1870 | BT31 | 1517 | 4753 | ||
| Margarita Copper Mining Co. Ltd | 1883-1903 | BT2 | 1279 | |||
| Margarita Mine Ltd | 1899 | BT31 | 16119 | 60305 | ||
| Mariquita & New Granada Mining Co. Ltd | Colombia | 1856 | BT31 | 155 | 470 | |
| Mariquita & New Granada Mining Co. Ltd Part 1 | Colombia | 1852 | BT41 | 429 | 2428 | |
| Mariquita & New Granada Mining Co. Ltd Part 2 | Colombia | BT41 | 430 | 2428 | ||
| Mariquita Mining Co. Ltd | 1866 | BT31 | 1253 | 3016 | ||
| Marmato Mining Co | BT41 | 428 | 2427 | |||
| Martington Moor Lead Mining Co. Ltd | 1878 | BT31 | 2409 | 12084 | ||
| Martin’s Mines Ltd | 1888 | BT31 | 4240 | 27476 | ||
| Maryborough Mining & Finance Co. Ltd | 1934 | BT31 | 33489 | 284539 | ||
| Matabele Mines Ltd | 1895 | BT31 | 6582 | 46326 | ||
| Matabele Proprietary Mines Ltd | 1900 | BT31 | 8935 | 65889 | ||
| Maurian Iron Mines Ltd | 1905 | BT31 | 11087 | 84386 | ||
| Mawston Lead Mining Co. Ltd | Youlgreave | Derbyshire | 1877 | BT31 | 2311 | 11186 |
| May Mining Co. Ltd | Cwmystwyth | Cardiganshire | 1911 | BT31 | 20193 | 117493 |
| Mayo Granite Co. Ltd | Ireland | 1888 | BT31 | 4126 | 26576 | |
| Mazarron Manganese Iron Ore Co. Ltd | 1891 | BT31 | 5109 | 34425 | ||
| Mazaruni (British Guiana) Diamond Mines Ltd | 1902 | BT31 | 9928 | 74030 | ||
| Mazoe Syndicate Ltd | 1893-1897 | BT2 | 2474 | |||
| McCoy Hill Silver Mining Co. Ltd | 1872 | BT31 | 1695 | 6076 | ||
| McHenry Mining Co. Ltd | 1874 | BT31 | 1943 | 8121 | ||
| Medina United Tin Mining Co. Ltd | 1868 | BT31 | 1385 | 3872 | ||
| Meldrum Tunnel & Mining Syndicate Ltd | nd | BT2 | 3432 | |||
| Melides Anglo Franceza Mining Co | BT41 | 436 | 2458 | |||
| Melilla Mining Co. Ltd | 1924 | BT31 | 28584 | 198934 | ||
| Melin Llyn Pair Silver Lead & Copper Mining Co. Ltd | Towyn | Merionethshire | 1882 | BT31 | 3093 | 17714 |
| Melindur Valley Lead Mining Co. Ltd | Goginan | Cardiganshire | 1873 | BT31 | 1912 | 7813 |
| Melkedalem Copper Mines Ltd | 1902 | BT31 | 9727 | 72449 | ||
| Melkedalen Copper Mines Ltd | 1899 | BT31 | 8704 | 63561 | ||
| Mellanear Copper Mine Co. Ltd | St Erth | Cornwall | 1876 | BT286 | 426 | |
| Mellanear Copper Mine Co. Ltd | St Erth | Cornwall | 1888 | BT286 | 120 | |
| Mellanear Mining Co. Ltd | St Erth | Cornwall | 1868 | BT286 | 159 | |
| Mellingloch Lead Mining Co. Ltd | Aberhafesp | Montgomeryshire | 1871 | BT31 | 1591 | 5278 |
| Melvin & Oriental Mines Ltd | 1903 | BT31 | 10377 | 78135 | ||
| Melyndwr Lead Mining Co. Ltd | Goginan | Cardiganshire | 1876 | BT31 | 2247 | 10700 |
| Mendip Hematite & Lead Mining Co. Ltd | Mendip | Somerset | 1872 | BT31 | 1772 | 6661 |
| Mendip Hills Mining Co. Ltd | Blagdon | Somerset | BT41 | 437 | 2465 | |
| Mendip Hills Mining Co. Ltd | Blagdon | Somerset | 1856 | BT31 | 197 | 594 |
| Menhenniot Silver Lead Mining Co. Ltd | Menheniot | Cornwall | 1873 | BT286 | 345 | |
| Menzenberg Mining Co. Ltd | Rhenish Prussia | Germany | 1871 | BT31 | 1643 | 5675 |
| Menzies United Mines Ltd | 1895 | BT31 | 6492 | 45715 | ||
| Meria Mining Co. of Corsica Ltd | 1877 | BT31 | 2390 | 11889 | ||
| Merioneth Consols Mining Co. Ltd | Llanfachreth | Merionethshire | 1872 | BT31 | 1676 | 5948 |
| Merioneth Mining Agency Co. Ltd | Merionethshire | 1881 | BT31 | 2842 | 15630 | |
| Merioneth Mining Co. Ltd | Merionethshire | 1872 | BT31 | 1719 | 6261 | |
| Merlin Hill & Pantyglein Mining Co. Ltd | Wales | 1860 | BT31 | 446 | 1726 | |
| Merlin Hill & Pantyglein Mining Co. Ltd | Wales | BT41 | 442 | 2479 | ||
| Merrybent & Middleton Tyas Mining & Smelting Co. Ltd | Melsonby | Yorkshire | 1865 | BT31 | 1107 | 2154C |
| Merrybent Mining Syndicate Ltd | Middleton Tyas | Yorkshire | 1910 | BT31 | 13302 | 110474 |
| Merryfield Mining Co. Ltd | Stonebeck Down | Yorkshire | 1857 | BT31 | 223 | 704 |
| Merryfield Mining Co. Ltd | Stonebeck Down | Yorkshire | BT41 | 442 | 2480 | |
| Mesquital Del Oro Mining Co. Ltd | Mexico | 1896 | BT31 | 7170 | 50625 | |
| Mesquital Del Oro Mining Co. Ltd | Mexico | 1885 | BT31 | 3540 | 21604 | |
| Mesquital Mines Ltd | 1899 | BT31 | 8577 | 62463 | ||
| Metal Band Mining Co. Ltd | Alston with Garrigill | Cumberland | 1883 | BT31 | 3117 | 17920 |
| Metals Smelting Works Ltd | 1891 | BT31 | 5049 | 33911 | ||
| Metcalfe & General Mining Co. of Jamaica | Jamaica | BT41 | 443 | 2485 | ||
| Meteor Diamond Mining Co. Ltd | 1881 | BT31 | 2819 | 15460 | ||
| Mexican & General Mines Syndicate Ltd | Mexico | 1906 | BT31 | 11422 | 87768 | |
| Mexican Explorations Ltd | Mexico | 1889 | BT31 | 15026 | 30006 | |
| Mexican Mines Development Co. Ltd | Mexico | 1904 | BT31 | 10656 | 80680 | |
| Mexican Mines Development Co. Ltd | Mexico | 1888 | BT31 | 4211 | 27251 | |
| Mexican Mines Proprietary Ltd | Mexico | 1905 | BT31 | 11072 | 84241 | |
| Mexican Mines Selection Syndicate Ltd | Mexico | 1901 | BT31 | 9327 | 69317 | |
| Mexican Mining & Development Co. Ltd | Mexico | 1909 | BT31 | 12829 | 103749 | |
| Mexican Mining & Industrial Corporation Ltd | Mexico | 1907 | BT31 | 18082 | 93216 | |
| Mexican San Felix Mines Ltd | Mexico | 1903 | BT31 | 10251 | 76983 | |
| Mexican Silver Lead Mines Ltd | Mexico | 1904 | BT31 | 10863 | 82443 | |
| Mexican Silver Mining Co. Ltd | Mexico | 1865 | BT31 | 1101 | 2122C | |
| Mexican Smelting Corporation Ltd | Mexico | 1906 | BT31 | 17853 | 89999 | |
| Mexican Smelting Mining & Land Corporation Ltd | Mexico | 1891 | BT31 | 5231 | 35517 | |
| Mexico-Orient Mining Syndicate Ltd | Mexico | 1908 | BT31 | 18549 | 99560 | |
| Michell Mine Syndicate Ltd | 1897 | BT31 | 7244 | 51232 | ||
| Michipicoten Native Copper Co. Ltd | Ontario | Canada | 1881 | BT31 | 2743 | 14894 |
| Michoacan San Francisco Copper Mines Syndicate Ltd | U.S.A. | 1897 | BT31 | 7455 | 52980 | |
| Mid Cornwall Mines Ltd | Cornwall | 1873 | BT286 | 337 | ||
| Mid Cumberland Silver Lead & Blende Mines Ltd | Caldbeck | Cumberland | 1888 | BT31 | 4116 | 26459 |
| Mid Devon Copper Mining Co. Ltd | Belstone | Devon | 1888 | BT286 | 100 | |
| Mid Devon Copper Mining Co. Ltd | Belstone | Devon | 1878 | BT286 | 455 | |
| Mid Moonta Copper Mines Ltd | Devon | 1898 | BT31 | 8181 | 59177 | |
| Mid Moonta Copper Mining Co. Ltd | South Australia | Australia | 1872 | BT31 | 1719 | 6260 |
| Mid Wales Lead Mining Co. Ltd | Llangurig | Montgomeryshire | 1867 | BT31 | 1356 | 3675 |
| Middleton Iron Co. Ltd | 1864 | BT31 | 935 | 1195C | ||
| Middletown Glaze Stone & Lead Mining Co. Ltd | 1874 | BT31 | 2010 | 8674 | ||
| Midland Mining Co. Ltd | MN | 1857 | BT31 | 244 | 794 | |
| Midland Mining Co. Ltd | MN | BT41 | 454 | 2554 | ||
| Midland Refractories Co. Ltd | 1917 | BT31 | 32234 | 146323 | ||
| Midlands Mining & Finance Syndicate Ltd | 1896 | BT31 | 15649 | 48869 | ||
| Midlothian Oil Co. Ltd | Midlothian | 1882-1887 | BT2 | 1104 | ||
| Mid-Wales Mines Ltd | Wales | 1896-1936 | BT2 | 3207 | ||
| Mill Green Mining Co. Ltd | Youlgreave | Derbyshire | 1862 | BT31 | 709 | 69C |
| Mill Town Mining Co * | Ashover | Derbyshire | 1857 | BT41 | 456 | 2564 |
| Millom Mining Co. Ltd | Millom | Cumberland | 1857 | BT31 | 239 | 779 |
| Millom Mining Co. Ltd | Millom | Cumberland | BT41 | 456 | 2563 | |
| Milltown Mining Co. | Ireland | 1857 | BT41 | 456 | 2564 | |
| Milltown Mining Co. Ltd | Ireland | 1857 | BT31 | 234 | 751 | |
| Milltown Mining Co. Ltd | Co. Clare | Ireland | 1857 | BT31 | 234 | 750 |
| Milwr Mining Co. Ltd | Milwr | Flintshire | 1888 | BT31 | 4235 | 27441 |
| Minah Consolidated Mining Co. Ltd | Montana | U.S.A. | 1889 | BT31 | 4621 | 30339 |
| Mine & Smelter Supply Co. Ltd | 1905 | BT31 | 11260 | 86052 | ||
| Mine Dust Removal Syndicate Ltd | 1905 | BT31 | 11001 | 83632 | ||
| Mine Head Land Co. Ltd | 1899 | BT31 | 8626 | 62900 | ||
| Mine Host Ltd | 1910 | BT31 | 13056 | 107086 | ||
| Mine Owners Association Ltd | 1886 | BT31 | 3744 | 23342 | ||
| Mine Owners’ Trust: Ltd | 1891 | BT31 | 4967 | 33175 | ||
| Minera Boundary & Lower Eisteddfod Mining Co. Ltd | Minera | Denbighshire | 1864 | BT31 | 886 | 948C |
| Minera Boundary Lead Mining Co. Ltd | Minera | Denbighshire | 1862 | BT31 | 645 | 2709 |
| Minera Consols Ltd | Wrexham | Denbighshire | 1883 | BT31 | 3270 | 19247 |
| Minera Lead Smelting & Desilverizing Co. Ltd | Minera | Denbighshire | 1882 | BT31 | 3027 | 17130 |
| Minera Mining Co * | Minera | Denbighshire | 1856 | BT41 | 459 | 2576 |
| Minera Mining Co. Ltd | Minera | Denbighshire | 1856 | BT31 | 132 | 415 |
| Minera Mountain Lead Mining Co. Ltd | Minera | Denbighshire | 1885 | BT31 | 3510 | 21372 |
| Minera Mountain Lead Mining Co. Ltd | Minera | Denbighshire | 1877 | BT31 | 2377 | 11778 |
| Minera Mountain Mining Syndicate Ltd | Minera | Denbighshire | 1892 | BT31 | 5354 | 36734 |
| Minera Ragman Mining Co. Ltd | Minera | Denbighshire | 1863 | BT31 | 774 | 403C |
| Minera Union Mining Co. Ltd | Minera | Denbighshire | 1862 | BT31 | 667 | 2830 |
| Minera Western Boundary Mining Co. Ltd | Minera | Denbighshire | 1864 | BT31 | 896 | 997C |
| Minera Western Boundary Mining Co. Ltd | Minera | Denbighshire | 1863 | BT31 | 817 | 618C |
| Mineral Corporation of Great Britain Ltd | Caernarvonshire | 1878 | BT31 | 2415 | 12144 | |
| Mineral Court Tin Mine Ltd | St Stephen in Brannel | Cornwall | 1863 | BT286 | 5 | |
| Mineral Hill Silver Mines Co. Ltd | Nevada | U.S.A. | 1871 | BT31 | 1619 | 5496 |
| Mineral Rights Association Ltd | Nicaragua | 1866 | BT31 | 1247 | 2976 | |
| Minerals Prospecting Syndicate Ltd | 1895 | BT31 | 6189 | 43859 | ||
| Mines & General Telpher Co. Ltd | 1889 | BT31 | 4352 | 28265 | ||
| Mines & General Trust Ltd | 1905 | BT31 | 10957 | 83219 | ||
| Mines & Investment Corporation Ltd | 1889 | BT31 | 4477 | 29218 | ||
| Mines & Lands of Rhodesia Development Co. Ltd | 1899 | BT31 | 8480 | 61697 | ||
| Mines & Lands Search Co. Ltd | 1895 | BT31 | 6417 | 45303 | ||
| Mines & Mercantile Finance Corporation Ltd | 1896 | BT31 | 7084 | 49919 | ||
| Mines & Minerals Exploration Syndicate Ltd | 1901 | BT31 | 9493 | 70530 | ||
| Mines & Options Syndicate Ltd | 1902 | BT31 | 9764 | 72724 | ||
| Mines Acquisition & Development Co. Ltd | 1895 | BT31 | 6224 | 44108 | ||
| Mines Agency Ltd | 1895 | BT31 | 6164 | 43678 | ||
| Mines Co. Ltd | 1886 | BT31 | 3757 | 23421 | ||
| Mines Corporation of New Zealand Ltd | 1897 | BT31 | 7426 | 52755 | ||
| Mines Corporation of New Zealand Ltd | 1896 | BT31 | 6926 | 48728 | ||
| Mines Development (South African) Co. Ltd | 1895 | BT31 | 6455 | 45493 | ||
| Mines Development Co. of Victoria Ltd | 1900 | BT31 | 9006 | 66611 | ||
| Mines Development Corporation Ltd | 1887 | BT31 | 3892 | 24585 | ||
| Mines Discovery Syndicate Ltd | 1902 | BT31 | 9983 | 74544 | ||
| Mines Drainage & Exploration Syndicate Ltd | 1891 | BT31 | 5220 | 35415 | ||
| Mines Examination Co. Ltd | 1882 | BT31 | 2959 | 16585 | ||
| Mines Exploitation Syndicate Ltd | 1894 | BT31 | 5962 | 42040 | ||
| Mines Exploration & Discovery Syndicate Ltd | 1895 | BT31 | 6227 | 44140 | ||
| Mines Finance Syndicate Ltd | 1891 | BT31 | 4999 | 33461 | ||
| Mines Intersection Syndicate Ltd | 1897 | BT31 | 7602 | 54256 | ||
| Mines Investment Association Ltd | 1880 | BT31 | 2604 | 13724 | ||
| Mines Investment Association of Turkey Ltd | 1870 | BT31 | 1530 | 4839 | ||
| Mines Investment Corporation Ltd | 1896 | BT31 | 6753 | 47512 | ||
| Mines Investment Corporation Ltd | 1896 | BT31 | 6608 | 46496 | ||
| Mines Issuing Syndicate Ltd | 1895 | BT31 | 6203 | 43966 | ||
| Mines Ltd | 1906 | BT31 | 11487 | 88468 | ||
| Mines Negotiation & Agency Ltd | 1896 | BT31 | 6869 | 48315 | ||
| Mines of Ecuador Ltd | 1901 | BT31 | 9495 | 70547 | ||
| Mines of Westralia Ltd | 1896 | BT31 | 7020 | 49448 | ||
| Mines Possession Co. Ltd | 1895 | BT31 | 6386 | 45105 | ||
| Mines Prospecting & Supply Syndicate Ltd | 1899 | BT31 | 8576 | 62454 | ||
| Mines Purchase & Finance Co. Ltd | 1866 | BT31 | 1237 | 2909C | ||
| Mines Purchase Syndicate Ltd | 1894 | BT31 | 6003 | 42378 | ||
| Mines Royal Ltd | 1895 | BT31 | 6183 | 43801 | ||
| Mines Selection Co. Ltd | 1895 | BT31 | 6229 | 44157 | ||
| Mines Selection Syndicate Ltd | 1892 | BT31 | 5336 | 36558 | ||
| Mines Share Trust Ltd | 1881 | BT31 | 2858 | 15747 | ||
| Mines Trust & Guarantee Corporation Ltd | 1899 | BT31 | 8326 | 60505 | ||
| Mines Trust Ltd | 1892 | BT31 | 5271 | 35934 | ||
| Mines Trust of British Columbia Ltd | 1896 | BT31 | 6962 | 49022 | ||
| Mining & Combustion Equipment Ltd Plain Vol. | 1952 | BT31 | 41512 | 508905 | ||
| Mining & Commodity Investment Co. Ltd Vol 1 | 1951 | BT31 | 39798 | 494522 | ||
| Mining & Finance Ltd | 1924 | BT31 | 28652 | 199749 | ||
| Mining & General Development Trust of Rhodesia Ltd | 1910 | BT31 | 19643 | 111653 | ||
| Mining & General Industries Ltd | 1910 | BT31 | 19520 | 110175 | ||
| Mining & General Investment Co. Ltd | 1873 | BT31 | 1895 | 7635 | ||
| Mining & General Investment Ltd | 1908 | BT31 | 32005 | 99917 | ||
| Mining & General Mutual Life Assurance Co | BT41 | 458 | 2568 | |||
| Mining & General Syndicate Ltd | 1874 | BT31 | 1938 | 8073 | ||
| Mining & General Syndicate of MexiCo. Ltd | 1920 | BT31 | 25548 | 163676 | ||
| Mining & General Trust of Canada, Ltd | 1914 | BT31 | 32185 | 135730 | ||
| Mining & Prospecting Co. Ltd | 1887 | BT31 | 3821 | 23987 | ||
| Mining & Smelting Co. Ltd | 1911 | BT31 | 13732 | 118241 | ||
| Mining & Smelting Co. Ltd | 1911 | BT31 | 13732 | 118241 | ||
| Mining Adventurers of Utah Ltd | Utah | U.S.A. | 1873 | BT31 | 1837 | 7172 |
| Mining Agency Ltd | 1914 | BT31 | 22082 | 134142 | ||
| Mining Association Ltd | 1909 | BT31 | 12795 | 103203 | ||
| Mining Association Ltd | 1867 | BT31 | 1359 | 3697 | ||
| Mining Claims Ltd | 1920 | BT31 | 25668 | 164857 | ||
| Mining Commercial & General Trust Ltd | 1910 | BT31 | 19333 | 108427 | ||
| Mining Concessions Ltd | 1934 | BT31 | 33541 | 291928 | ||
| Mining Concessions Ltd | 1910 | BT31 | 19696 | 112337 | ||
| Mining Corporation of Lower California Ltd | California | U.S.A. | 1909 | BT31 | 12963 | 105654 |
| Mining Development Syndicate (of Colorado) Ltd | 1892-1906 | BT2 | 2371 | |||
| Mining Direction Co. Ltd | 1913 | BT31 | 21268 | 127446 | ||
| Mining Economies Ltd | 1920 | BT31 | 25628 | 164457 | ||
| Mining Estates Co. Ltd | 1880 | BT31 | 2729 | 14772 | ||
| Mining Expander Co. Ltd | 1910 | BT31 | 19780 | 113292 | ||
| Mining Industries (Exports & Imports) Ltd | 1981 | BT2 | 1981 | 46133 | ||
| Mining Industries Manufacturing Ltd | 1981 | BT2 | 1981 | 48738 | ||
| Mining Investment Co | BT41 | 458 | 2569 | |||
| Mining Investment Company of Glasgow Ltd | 1892 | BT2 | 2412 | |||
| Mining Investment Registry Ltd | 1907 | BT31 | 12175 | 95547 | ||
| Mining Issues Ltd | 1906 | BT31 | 11401 | 87515 | ||
| Mining Negotiators Ltd | 1909 | BT31 | 18789 | 102390 | ||
| Mining Properties & General Trading Co. Ltd | 1911 | BT31 | 19798 | 113505 | ||
| Mining Requirements Co. Ltd | 1922 | BT31 | 26984 | 179071 | ||
| Mining Rights Ltd | 1935 | BT31 | 33570 | 296337 | ||
| Mining Securities Ltd | 1934 | BT31 | 35612 | 291094 | ||
| Mining Selection Trust Ltd | 1926 | BT31 | 32785 | 217454 | ||
| Mining Shares Investment Co. Ltd | 1864 | BT31 | 954 | 1294C | ||
| Mining Supply & Contract Co. Ltd | 1882 | BT31 | 3015 | 17034 | ||
| Mining Syndicate Ltd | 1906 | BT31 | 11690 | 90500 | ||
| Mining Syndicate Ltd | MN | 1881 | BT31 | 2896 | 16079 | |
| Mining Trust Ltd | 1929 | BT31 | 35495 | 239950 | ||
| Mining Trust Ltd | Cornwall | 1880 | BT286 | 497 | ||
| Mining Ventures Ltd | 1910 | BT31 | 13118 | 107987 | ||
| Mining Ventures Ltd | 1936 | BT31 | 33678 | 319429 | ||
| Minsterley Mines Ltd | Minsterley | Shropshire | 1898 | BT31 | 7814 | 55919 |
| Miradani Mining Co. Ltd | 1935 | BT31 | 33917 | 307081 | ||
| Missouri Lead Mining & Smelting Co. Ltd | Missouri | U.S.A. | 1879 | BT31 | 2513 | 12982 |
| Moel Hebog Copper Mining Co. Ltd | Dolbenmaen | Caernarvonshire | 1886 | BT31 | 3705 | 23048 |
| Moelfre Lead Mining Co. Ltd | Llanidloes | Montgomeryshire | 1881 | BT31 | 2871 | 15847 |
| Mogshaw Rake & Airedale Vein Mining Co. Ltd | Monyash | Derbyshire | BT41 | 460 | 2578 | |
| Mogshaw Rake & Airedale Vein Mining Co. Ltd | Bakewell | Derbyshire | 1859 | BT31 | 441 | 1701 |
| Mohochang Mining Syndicate Ltd | 1908 | BT31 | 12306 | 97041 | ||
| Mold Consolidated Lead Mining Co. Ltd | Mold | Flintshire | 1865 | BT31 | 1148 | 2399C |
| Mold District Lead Co. Ltd | Mold | Flintshire | 1885 | BT31 | 3476 | 21066 |
| Mold Lead Mining Co. Ltd | Mold | Flintshire | 1856 | BT31 | 200 | 603 |
| Mold Lead Mining Co. Ltd | Mold | Flintshire | BT41 | 460 | 2579 | |
| Mold Mines Ltd | Mold | Flintshire | 1868 | BT31 | 1401 | 3988 |
| Mold Mines Ltd | Mold | Flintshire | 1874 | BT31 | 2049 | 8967 |
| Mona & Parys Mines Ltd | Amlwch | Anglesey | 1899 | BT31 | 16117 | 60279 |
| Mona Consols Copper Mining Co. Ltd | Amlwch | Anglesey | 1881 | BT31 | 2829 | 15538 |
| Mona Copper Co. Ltd | Amlwch | Anglesey | 1928 | BT31 | 32995 | 233691 |
| Mona Mines Ltd | Amlwch | Anglesey | 1880 | BT31 | 2600 | 13702 |
| Monaghan Mining Co. Ltd | Ireland | 1890 | BT31 | 4858 | 32248 | |
| Monarch & Chalk Creek Mining Co. Ltd | 1880 | BT31 | 2655 | 14132 | ||
| Monarch Copper Co. Ltd | Wales | 1883 | BT31 | 3257 | 19139 | |
| Monastery Diamond Mines & Estates Co. Ltd | 1904 | BT31 | 10809 | 81966 | ||
| Monitor Mines Ltd | 1887 | BT31 | 3872 | 24439 | ||
| Monklands Quarrying & Mining Co. Ltd | 1986 | BT2 | 1986 | 79627 | ||
| Monkston Manganese Mine Ltd | Brentor | Devon | 1888 | BT286 | 114 | |
| Monkston Manganese Mine Ltd | Brentor | Devon | 1881 | BT286 | 528 | |
| Monkston Manganese Mining Co. Ltd | Brentor | Devon | 1871 | BT31 | 1636 | 5615 |
| Monsal Dale Spar Mine Ltd | Great Longstone | Denbighshire | 1912 | BT31 | 20563 | 121096 |
| Mont Alegre Silver Mining Co. Ltd | 1874-1877 | BT2 | 550 | |||
| Montague Mine Ltd | 1897 | BT31 | 7667 | 54726 | ||
| Montana Co. Ltd | Montana | U.S.A. | 1883 | BT31 | 3103 | 17787 |
| Montana-London Mining Development Syndicate Ltd | 1909 | BT31 | 12854 | 104089 | ||
| Monte Albo Mining Co. Ltd | Italy | 1870 | BT31 | 1529 | 4838 | |
| Monte Catini Copper Mining Co. Ltd | Italy | 1882 | BT31 | 2918 | 16258 | |
| Monte Del Oro Mining Co. Ltd | Spain | 1886 | BT31 | 3740 | 23306 | |
| Monte Mor Mining Co. Ltd | 1881 | BT31 | 2873 | 15866 | ||
| Monte Rosa Copper Mining & Smelting Co. Ltd | 1867 | BT31 | 1338 | 3523 | ||
| Monte Rosa Mining Co. Ltd | 1870 | BT31 | 1511 | 4725 | ||
| Montejo Mines Ltd | 1900 | BT31 | 8868 | 65248 | ||
| Montezuma Silver Mines of Mexico Ltd | 1883 | BT31 | 3265 | 19209 | ||
| Montpellier Silver Lead Mining Co. Ltd | Ballaugh | Isle of Man | 1875 | BT31 | 2169 | 10105 |
| Monydd Gorddu Lead Mine Co. Ltd | Bow Street | Cardiganshire | 1873 | BT31 | 1869 | 7392 |
| Moorina Tin Mine Ltd | 1900 | BT31 | 8965 | 66161 | ||
| Moray Firth Mining Co. Ltd | Scotland | 1880 | BT31 | 2609 | 13772 | |
| Morenci Copper Mines Ltd | 1899 | BT31 | 8549 | 62248 | ||
| Morfa Du Mining Co. Ltd | Amlwch | Anglesey | 1877 | BT31 | 2378 | 11788 |
| Morfa Iron Ore Co | Llanaelhaiarn | Caernarvonshire | 1871 | BT31 | 1596 | 5328 |
| Morley Victoria Quarry Co. Ltd | Morley | Yorkshire | 1877 | BT31 | 2320 | 11249 |
| Morocco Riff Mining Syndicate Ltd | 1912 | BT31 | 20509 | 120595 | ||
| Morro Grande Mines Syndicate Ltd | 1891 | BT31 | 5214 | 35342 | ||
| Morvah Consols Tin Mining Co. Ltd | Morvah | Cornwall | 1871 | BT286 | 246 | |
| Moselle Mines Ltd | Rhenish Prussia | Germany | 1881 | BT31 | 2822 | 15483 |
| Moss Bay Hematite Iron & Steel Co | Egremont | Cumberland | 1891 | BT31 | 5021 | 33663 |
| Moss Bay Hematite Iron & Steel Co | Egremont | Cumberland | 1881 | BT31 | 2761 | 15042 |
| Mossdale Lead Mining Co. Ltd | Conistone with Kilnsey | Yorkshire | 1872 | BT31 | 1698 | 6102 |
| Mostyn Consols Silver Lead Mining Co. Ltd | Whitford | Flintshire | 1880 | BT31 | 2649 | 14079 |
| Mostyn Copper Co. Ltd | Whitford | Flintshire | 1865 | BT31 | 1070 | 1941C |
| Mostyn Silver Lead & Blende Co. Ltd | Whitford | Flintshire | 1876 | BT31 | 2175 | 10161 |
| Mottram St Andrew Mining Co. Ltd | Mottram St Andrew | Cheshire | 1861 | BT31 | 530 | 2128 |
| Mount Albion Silver Mining & Smelting Co. Ltd | 1887 | BT31 | 3993 | 25399 | ||
| Mount Carbis Mine | Redruth | Cornwall | 1888 | BT286 | 122 | |
| Mount Carbis Mine | St Austell | Cornwall | 1888 | BT286 | 591 | |
| Mount Cattlin Copper Mining Co. Ltd | 1906 | BT31 | 11694 | 90532 | ||
| Mount Chalmers Copper Mines Ltd | 1899 | BT31 | 8672 | 63263 | ||
| Mount Dalby Silver Lead Mining Co. Ltd | Dalby | Isle of Man | 1871 | BT31 | 1659 | 5814 |
| Mount Erins Copper Mining Co. Ltd | Ireland | 1859 | BT31 | 410 | 1576 | |
| Mount Erins Copper Mining Co. Ltd | Ireland | BT41 | 464 | 2602 | ||
| Mount Fraser Copper Mines (N.S.W.) Ltd | 1900 | BT31 | 8906 | 65612 | ||
| Mount Gabriel Barytes & Umber Co. Ltd | Ireland | 1895 | BT31 | 6359 | 44916 | |
| Mount Gabriel Copper Mining Co. Ltd | Ireland | 1868 | BT31 | 1385 | 3873 | |
| Mount Gabriel Mineral Co. Ltd | Ireland | 1856 | BT41 | 464 | 2603 | |
| Mount Gabriel Mineral Company Ltd | Ireland | 1856 | BT31 | 7 | 46 | |
| Mount Leyshon (Queensland) Ltd | Queensland | Australia | 1887 | BT31 | 3792 | 23734 |
| Mount Lyell Consolidated Mines Ltd | 1897 | BT31 | 7723 | 55199 | ||
| Mount Lyell Proprietary Mines Ltd | 1898 | BT31 | 7761 | 55491 | ||
| Mount Malcolm Mines Ltd | 1900 | BT31 | 8882 | 65379 | ||
| Mount Remarkable Mining Co. Ltd | 1911 | BT31 | 13535 | 114418 | ||
| Mount Wellington Ltd | Mount Wellington | Cornwall | 1934 | BT31 | 35619 | 293236 |
| Mount Wheeler Syndicate Ltd | 1889-1906 | BT2 | 1867 | |||
| Mountain Chief Mining Co. of Utah Ltd | Utah | U.S.A. | 1872 | BT31 | 1757 | 6555 |
| Mountain Mines Ltd | 1895 | BT31 | 6327 | 44733 | ||
| Mounts Bay Tin & Copper Mining Co. Ltd | Breage | Cornwall | 1876 | BT286 | 419 | |
| Mozambique Consolidated Mines Ltd | 1898 | BT31 | 7784 | 55648 | ||
| Mozambique Consolidated Mines Ltd | 1897 | BT31 | 7549 | 53790 | ||
| Mozambique Mines Ltd | 1904 | BT31 | 10657 | 80681 | ||
| Mulberry Tin Works Ltd | Withiel | Cornwall | 1882 | BT31 | 2949 | 16500 |
| Mulberry Tin Works Ltd | Withiel | Cornwall | 1906 | BT31 | 11569 | 89265 |
| Munster Consolidated Mining Co. Ltd | Co. Cork and County Kerry | Ireland | 1861 | BT31 | 579 | 2400 |
| Murchison Prospecting Syndicate Ltd | 1895 | BT31 | 6111 | 43292 | ||
| Murcia Mines Co. Ltd | 1889 | BT31 | 4381 | 28464 | ||
| Murcia Mining Co. Ltd | 1880 | BT31 | 2609 | 13773 | ||
| Murcon Mining Ltd | 1985 | BT2 | 1985 | 61746 | ||
| Murillo Silver Mine Ltd | 1889 | BT31 | 4578 | 29976 | ||
| Murphy Mining Ltd | 1982 | BT2 | 1982 | 63613 | ||
| Murrin Copper Mines Ltd | 1902 | BT31 | 10007 | 74768 | ||
| Mutual Mining & Commercial Trust Ltd | 1913 | BT31 | 21386 | 128382 | ||
| Mutual Mining & Commercial Trust Ltd | 1909 | BT31 | 12770 | 102858 | ||
| Mwnbwll Lead Mining Co. Ltd | Mold | Flintshire | 1872 | BT31 | 1774 | 6681 |
| Mydrim Mining Co. Ltd | Mydrim | Carmarthenshire | 1860 | BT31 | 504 | 1999 |
| Mydrim Mining Co. Ltd | Mydrim | Carmarthenshire | BT41 | 465 | 2616 | |
| Mynach Vale Mining Co. Ltd | Devil’s Bridge | Cardiganshire | 1882 | BT31 | 2950 | 16513 |
| Mynydd Gorddu Lead Mine Ltd | Bow Street | Cardiganshire | 1880 | BT31 | 2595 | 13652 |
