The following is a list of the number bands allocated to the various types of locomotive and multiple unit operated by British Railways (and successors) since the mid-1960s. TOPS has been modified over the years, and there are a number of areas of overlap especially where a number band has been exhausted.

Diesel Locomotives (01-79)

01-13 Diesel Shunters
14-20 Type 1 (1000hp or less)
21-31 Type 2 (1001-1499hp)
32-39 Type 3 (1500-1999hp)
40-54 (and 57) Type 4 (2000-2999hp)
55-79 Type 5 (3000hp plus)

Electric Locomotives (70-96)

70-79 DC powered and electro-diesel
80-96 AC powered

Diesel Multiple Units (100-299, 600-699)

100-199 Diesel mechanical
200-299 Diesel electric
600-699 New DMU allocation, as yet not used

Electric Multiple Units (300-899)*

300-399 AC powered (original allocation)
400-499 DC powered (Southern Region)
500-599 Other DC powered
700-799 AC/DC powered (new allocation)
800-899 New high speed units

* Bi-mode units (e.g. AC and DC powered) tended to be listed under the 3xx range

There are also numbers allocated to departmental vehicles and other special vehicles in the 9xxs.