Energy watchdog Ofgem has found that 18 gas and electricity suppliers overcharged customers when they switched to better deals.

Here is the list of suppliers and compensation bills:

Supplier, Number of customers affected, Total redress

– Bristol Energy 12,617 £56,552.64– British Gas 141,415 £1,269,095.47– E 20,870 £72,772.93– E.On 28,126 £238,884.29– EDF 79,083 £516,191.55– Engie 9,061 £21,218.74– ESB Energy 1,961 £49,787.00– Green Star 79,083 £808,351.00– Energy npower 2,030 £25,602.69– Octopus Energy 19,712 £121,444.52– Orbit 723 £7,081.12– OVO Energy 240,563 £2,801,231.51– PFP Energy 5,347 £50,929.31– Scottish Power 157,236 £1,967,465.28– Shell 225,823 £1,217,203.40– So Energy 10,514 £78,480.89– SSE 132,620 £983,334.45– Utility Warehouse 2,723 £95,512.15