The Machine Gun Corps was the first unit to use Tanks in the British Army. They later became the Tanks Corps.
The strength of the Machine Gun Corps (Heavy) was recorded from June, 1916, until March, 1920, on a month-by-month basis.
At its peak, in May, 1916, it consisted of 2,956 officers and 25,828 other ranks - a total of 28,784 all ranks. A more detailed analysis is available on the MGC strength page.
| Battalion | Theatre | Date in theatre | Notes |
| "A" | France & Flanders | July 1917 | Later became No. 1 Tank Battalion |
| "B" | France & Flanders | July 1917 | Later became No. 2 Tank Battalion |
| "C" | France & Flanders | July 1917 | Later became No. 3 Tank Battalion |
| "D" | France & Flanders | July 1917 | Later became No. 4 Tank Battalion |
| "E" | France & Flanders | July 1917 | Later became No. 5 Tank Battalion |
| Egyptian Expeditionary Force | April 1917 | ||
| "F" | France & Flanders | July 1917 | Later became No. 6 Tank Battalion |
| "G" | France & Flanders | July 1917 | Later became No. 7 Tank Battalion |
| "H" | France & Flanders | September 1917 | Later became No. 8 Tank Battalion |
| "I" | France & Flanders | September 1917 | Later became No. 9 Tank Battalion |