Ovo Energy Ltd. and Good Energy Ltd. will repay a combined £4 million ($4.99 million) for overcharging customers during the energy crisis when household budgets were most squeezed.

Energy customers who have been overcharged will be repaid a total of £2.7 million from the two suppliers, while £1.25 million will be put in Ofgem’s voluntary redress fund in recognition of the suppliers’ failure to apply the price protections put in place at the height of the energy crisis, according to the energy regulator.

“It is totally unacceptable that Good Energy and OVO Energy customers were overcharged, particularly at a time that is already so challenging and stressful for consumers across the UK,” said Dan Norton, Ofgem’s deputy director of retail. “Energy suppliers should hear this loud and clear: we expect suppliers to act with the utmost care and integrity.”

Even with the government’s price support to help lower bills, there are 7.5 million households in energy poverty in Britain. Overdue debt is ballooning with customers unable to pay their supplier, according to lobby group EnergyUK. That threatens to bring further instability to an already fragile industry.

Ballooning Customer Debt Is Next Problem for UK Energy Suppliers

There were 18,000 customers who were charged above the maximum rates allowed under either the energy price cap or the government’s Energy Price Guarantee, put in place to protect consumers.