Ofgem has confirmed that energy suppliers wrote off more than £172 million in charges for almost one million customers under backbilling protections, according to figures covering 20241. The same figures show that around 11 million energy bills were issued at least a month late, including 3.5 million sent between three and 12 months after they were due1.
Under Ofgem's rules, suppliers generally cannot charge domestic customers for gas or electricity used more than 12 months ago if they failed to issue an accurate bill and the customer was not responsible for the delay1. The regulator's back billing rules cover cases where a supplier has not sent bills, has issued inaccurate bills, or has failed to act on information needed to calculate charges correctly1.
The protection is not automatic for every late bill. Customers may not qualify if they have deliberately avoided paying bills or unreasonably prevented their supplier from obtaining accurate meter readings, and the rules do not cancel debts that were correctly billed previously but remain unpaid1. Ofgem advises customers to check the dates covered by unexpected charges and contact their supplier if they believe the backbilling rules apply1.
Arielle Flynn, head of advice at UK Debt Expert, said households should examine an unexpected bill before agreeing to pay:
"If your energy bill is much higher than you expected, don't panic or automatically assume the amount is correct."
She added that customers should check the billing period, the meter readings used and whether the supplier relied on estimated readings, and ask for a breakdown of how the bill was calculated1.
On payment difficulties, Ofgem requires suppliers to work with customers, including considering their ability to pay when arranging repayment plans1. Customers can also ask about hardship funds and grants1. Where a complaint remains unresolved after eight weeks, or the supplier issues a deadlock letter, the dispute can be referred to the Energy Ombudsman1. The Ofgem overview sets out the regulator's wider remit, and the complaints and redress guide covers how disputes escalate.
Why it matters for households
A back bill can arrive months or years after the energy was used, and it can be large. The write-off figures show that the 12 month limit is being applied at scale: almost one million customers had charges cancelled in 20241. For a household, the rule limits how far a supplier can reach back when the delay is the supplier's fault, which matters most where a meter has not been read or a bill has been estimated for a long period.
The scale of late billing, with around 11 million bills at least a month late and 3.5 million between three and 12 months late, also indicates how often estimated or delayed charges build up before a corrected bill arrives1. That affects budgeting and the accuracy of any comparison of energy bills and energy independence, since a household's recorded spend may not reflect what it will eventually be charged.
The protection does not extend to debt that was correctly billed and left unpaid, so a written-off charge and an unpaid debt are treated differently1. The figures do not report how the £172 million was distributed across suppliers or regions, and no breakdown by nation has been published1.
What happens next
No further steps have been reported. Ofgem's published guidance on backbilling and on complaining about a supplier remains the reference point for households challenging a charge1.