When Clare Crisp received an email from her energy provider, Shell Energy last November, she was shocked and confused. Her direct debit had been nearly doubled from £72 to £130 per month, despite her account previously being £148 in credit. "I looked at my bills and thought: what on earth has gone on?" she says. Eventually she worked out what the energy firm had done. It had gone back five-and-a-half years, cancelled her previous electricity bills and re-billed her with higher amounts, adding up to an extra cost of £512.

It looked as though Shell Energy had looked back over her billing history, decided that she hadn't been paying enough and charged her for it now. In 2018, the energy regulator, Ofgem, banned companies from issuing these kinds of catch-up bills for energy used more than 12 months earlier. The ban was introduced to ensure customers such as Clare wouldn't be left struggling financially, or even in debt, after receiving unexpected bills. Shell Energy says that once it was notified of the mistake, it was corrected. Clare's account was refunded with the full amount of £512 and her direct debit amended.

It also added that all of its customer accounts were monitored by "dedicated teams". Rising complaints

Figures released to BBC News by the Energy Ombudsman show that it resolved 2,539 complaints about back-billing in 2019, the first full year in which the ban applied. This was an increase of more than a third, from 1,903 complaints in 2018. It also said more complaints were upheld last year. The Energy Ombudsman is responsible for looking into complaints about energy suppliers if customers are unhappy with the outcome or have not received a timely response from the company. It can also make a supplier change its decision

Source: BBC News Business