Prior to the introduction of TOPS, electric multiple unit numbers were allocated by British Rail regions in their own series.
The table below shows the series used by Tyseley depot (in the Western Region until 9 September 1963).
Inter-depot transfers meant frequent renumbering of sets, so that in about 1970 the fleet was renumbered into a common Region-wide series and from about 1972 permanent set numbers began to be painted (or applied by transfers) onto the ends of units, beneath the right-hand driver's cab window (as viewed looking directly at the front of the unit).
Sprinter (Class 15x) units carried the last three digits of their carriage numbers in the 52xxx and 57xxx series.
Refurbished class 117 and 122 kept their Tyseley 3xx and Laira (Western Region) 1xx unit numbers respectively.