Energy firms must prioritise vulnerable customers and contact those who miss payments in a crackdown on customer service standards by regulator Ofgem.

The new rules, which take effect from December 14, will require firms to contact customers if they miss two monthly or one quarterly payment, check to see if they are struggling with bills and, if so, offer support such as affordable payment plans or repayment holidays.

Suppliers will also have to publish their Citizens Advice customer service rating to allow consumers to compare them on call waiting times and the quality of their help.

The new standards, developed following a consultation this summer, aim to make it easier for customers to contact their suppliers, ensure struggling households are supported and improve overall customer satisfaction.

In a speech to the Energy UK conference on Wednesday, Ofgem chief executive Jonathan Brearley warns suppliers that the regulator will “not hesitate” to take action, pointing to recent examples of firms having to make multimillion-pound payments for poor customer service such as unacceptably long call waiting times and call drop-off rates.

Mr Brearley said: “With recent global events increasing pressure on gas prices, it’s likely that bills will rise further.

“This is why the industry needs to do all it can to ensure good customer services and provide help with managing debt, especially for the most vulnerable.

“In the last year, we have seen some good examples of suppliers stepping up their support for customers. However, despite this, the feeling of those on the frontline working with vulnerable households is that more still needs to be done.

“Long wait times to speak to someone on the phone; letters not replied to; lack of empathy for people’s personal circumstances. This needs to change, and today we are setting out our expectations of suppliers this winter, and how they will be held to account to ensure consumers can get hold of them more easily.

“In particular for vulnerable customers, we expect more proactivity and a more sympathetic response.”

Gillian Cooper, head of energy policy at Citizens Advice, said: “Aggressive debt collection by energy suppliers can make a difficult situation so much worse for struggling households. In an era of high energy prices and record energy debts, treating customers fairly is more important than ever. Any firm letting its customers down should rightly expect enforcement action.

“Ofgem is also right to make sure struggling customers can easily contact their supplier. Poor performance here will be reflected in our star rating which all suppliers will now be required to publish.

“If you have energy debt it’s important to speak to your supplier as soon as possible.”

Simon Francis, coordinator of the End Fuel Poverty Coalition, said: “It’s not enough for energy firms to just pick up the phone to customers struggling with their bills. With soaring energy debt levels, people need to have their concerns dealt with efficiently and in a sympathetic manner.

“We hope that as the new guidance is implemented, Ofgem will expand the measures it uses to assess energy firms’ performance. As well as ‘contact ease’ being measured and published, the regulator should also consider ‘contact success’ and ‘contact empathy’ as measures of performance for energy firms.”