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Back Billing vs Catch-Up Bill
People weaken complaints by calling every large bill a back bill. Use this page to identify whether the supplier is recovering old charges or correcting previous estimates.
Use together
Difference table
| Question | Back billing | Catch-up bill |
|---|---|---|
| What is it? | A supplier trying to recover charges for older energy that was not billed correctly. | A larger bill caused by replacing estimates with actual readings or correcting underpayment. |
| Main evidence | Bill date, supply period, statement history and old usage period. | Reading history, estimated vs actual readings and usage pattern. |
| Best wording | Ask how the 12-month rule applies and what exception is relied on. | Ask for a corrected reading history and calculation breakdown. |
| Likely remedy | Remove protected old charges or rebill eligible period. | Rebill accurately, explain balance and offer payment support if needed. |
If the bill includes both recent catch-up and old protected charges, split the complaint into two parts. Do not argue the whole balance as one vague problem.
Frequently asked questions
Can one bill contain both?
Yes. A bill can include recent corrected usage and older charges. Ask for a period-by-period breakdown.
Which page should I use first?
If the bill covers usage more than 12 months old, start with the back-billing rules page. If it is mainly estimate correction, start with estimated readings.
Can I still ask for a payment plan?
Yes. A valid catch-up bill can still be unaffordable, but affordability is a different issue from whether the charge is allowed.
Official sources used for this page
BillDecoded translates official process and billing information into practical checks. It is not affiliated with the Ombudsman, Ofgem, Citizens Advice, Which? or any supplier.