Challenge a shock energy bill and use back-billing rules

This guide is for households in Great Britain hit by an unexpectedly large gas or electricity bill, often a catch-up bill after months of estimates, a smart meter problem or a change of supplier. Suppliers do make mistakes, and Ofgem's back-billing rules can stop you being charged for energy used more than 12 months ago in many cases. You will check the bill against your meter, rebuild the charges yourself, decide whether back-billing applies and make a formal complaint that keeps debt action at bay. At the end you will have a corrected bill or a complaint ready for the Energy Ombudsman, plus a routine that stops it happening again.

What is inside

• Full step-by-step method8 detailed steps with decision points
• Ready-to-use templatesBack-billing dispute letter · Bill check worksheet · Phone script for the first call
• Timed action plan7 stages from “Day 1” to “Every month after”
• Costly mistakes to avoid4 traps and what to do instead
• Complete checklist11 items to tick off
• Insider tips and fixes4 tips and 4 common problems solved

Step by step

1. Pause, protect yourself and open a dispute

   Do not ignore the bill and do not pay a large disputed sum straight away. Contact the supplier, say "I am disputing this bill and want it treated as a complaint", and ask for a complaint reference number and written confirmation. Ask them to put the disputed amount on hold, not to pass it to debt collectors and not to change your payment method while they investigate. Keep paying for your current usage, for example your normal Direct Debit, so that no fresh arrears build up. If you are struggling to pay anything, or someone in your home is older, disabled or has a health condition, ask to be added to the Priority Services Register and tell the supplier about your circumstances. Start a log of every call, email and letter with the date, name and what was said.