npower's price rise is the fourth of the Big Six suppliers' hike this summer. British Gas, ScottishPower, E.ON & SSE customers have already been hit.

Customers are switching fast to avoid their bills going up.

Energyhelpline.com offer £20 commission for all switches plus £20 bonuses for multiples of 5 switches achieved during a period. Typical savings are £252 but can be up to £453 for larger households.