Ofgem has closed its investigation into what went wrong when British Gas changed prepayment top-up provider and left customers in the lurch. The supplier has agreed to pay £1.48m back to affected households and £250,000 into the energy redress fund.

There were no technical issues in the change of provider from Paypoint to Payzone from 1 January this year, but British Gas failed to adequately communicate changes in time, said the regulator, and its notification lacked telephone contact details. Meanwhile the British Gas chose not to operate its general enquiries line on New Year’s day, when the switch went live.

Worse, some 270,000 customers did not receive any notification ahead of the switch, which also raised minimum payment from £1 to £5. They may have opted out of marketing communications, but Ofgem said that a change of this nature should have been communicated. Failure to reach them “very probably” led some vulnerable people to go off supply at the coldest time of the year, it said.

British Gas has paid out £1,478,070 to affected customers, with £2,435 left to pay, per Ofgem’s notice.