| Machine | Company | Location | Installed |
|---|---|---|---|
| Leo II/1 | J. Lyons & Co. Ltd | London | May 1957 |
| Leo II/2 | W.D. & H.O. Wills | Bristol | Sept 1958 |
| Leo II/3 | Stewarts & Lloyds Ltd | Corby | June 1958 |
| Leo II/4 | Ford Motor Co. (parts) | Aveley | Dec 1958 |
| Leo II/5 | Leo Computers Ltd (Bureau) | London | Jul 1959 |
| Leo II/6 | Ministry of Pensions & National Insurance | Newcastle | Nov 1959 |
| Leo II/7 | British Oxygen Co. then Leo Bureau |
Edmonton | Feb 1960 |
| Leo II/8 c | Standard Motor Co. | Coventry | Jul 1960 |
| Leo II/9 c | Ilford Ltd.(films) | Ilford | Nov 1960 |
| Leo II/10 c | W.D. & H.O. Wills | Bristol | Apr 1961 |
| Leo II/11 c | Ford Motor Co. (payroll) | Dagenham | Jan 1961 |
'c' signifies Core memory with transistors and valves.
