Around 145,000 mains gas customers in Northern Ireland will see prices increase by an average £39/year from 1 April, as SSE Airtricity hikes prices by 7.8%.
Households on E.on's standard variable tariff will see their energy bills rise by an average of £22/year after the big six firm announced a series of changes to the way it charges customers.
Gas and electricity supplier Spark Energy has apologised after a debt collection firm contacted a number of its ex-customers and wrongly told them they owed money - even though some closed their accounts years ago.