The rate of exchange that determines the amount of pension that needs to be sacrificed to provide a given lump sum benefit at retirement. The commutation factor indicates how much cash is available for each £1 of pension exchanged. Scheme rules specify the commutation factor that will apply either to all members or specifically to individuals. The commutation factor is a ratio, e.g. 12:1 mean a pension of £883 per annum can be exchanged for a lump sum of £10,000.