Under Ofgem rules, British Gas must pay £30 compensation for each missed appointment, and another £30 for non-payment within 10 days. Suppliers and agents must also meet minimum standards of customer service under Ofgem’s Guaranteed Standards.

Around 12,000, largely business, customers were affected.

This year, British Gas reported to Ofgem that, due to process errors, it hadn’t paid compensation to some micro-business and domestic customers when agents missed appointments or did not keep them on time.

British Gas said it had been working with its supplier to make improvements. The supplier has since taken action to change its customer services processes. As such, Ofgem is not taking formal enforcement action.

Martin Crouch, Ofgem Senior Partner for Improving Regulation, said: “British Gas did the right thing in coming forward to report this issue, and has since improved its processes to make sure that, when appointments are missed or not kept on time, all customers receive the compensation they’re entitled to.

“It’s crucial that suppliers keep appointments on time, and make amends when things go wrong.”