Hold the Line Home Mindset Using AI Claude Skills How it was built
This is free, self-directed information, not advice. It is not legal advice, financial advice, or debt counselling or debt adjusting, and it is not a paid service. You act for yourself at every step. For advice on your own situation, use the free services named below or speak to a solicitor. Every effort is made to keep this material accurate and up to date, but the producers of this website cannot be held liable.
Hold the Line

Surprise Energy Back Bills

A sudden catch-up bill for energy you used months or years ago. If the supplier was at fault, there is a hard limit on how far back they can charge.

A guide to using AI to assert your rights as a human, calmly and on the facts. We use AI to do this work. We suggest you do too.

Two ways to use this guide, both free

You do not have to use AI. These guides work on their own. AI just makes it faster.

1

Let Claude do the work

The AI assistant reads your letter, works out your stage, and drafts what you need to send. You just answer its questions.

Start with Claude →
2

Or do it yourself

Work through the stages at your own pace, in plain English. No AI needed.

Work through it yourself →

New to Claude, or not sure what it is? It is free, here is how to start.

Get the full experience

Turn Claude into your personal surprise energy back bills case manager

+

Tap the plus to set this up.

You can copy the prompts on this page into Claude one at a time. Or you can install the Case Manager skill once, and Claude will walk you through your whole case from start to finish, every time, without you having to explain it again.

  1. Download the skill file below.
  2. In Claude, open Customize in the left sidebar, then the Skills tab.
  3. Click the + button, choose Create skill, and upload the file. Claude reads it automatically.
  4. Make sure the skill is toggled on.
  5. In Cowork, type / to pick it, or just say what's happened and Claude will use it.
Download the skill file

Requires "Code execution and file creation" to be enabled in Settings. The skill stays private to your account.

Free Claude does not install skills, but you do not need it to. Copy the prompt below into Claude at claude.ai and it will act as your case manager for this conversation.

I have had a surprise energy back bill and I want help. Act as my Energy Back-Billing Case Manager and walk me through this slowly and calmly, one step at a time, the way a patient adviser sitting beside me would. Please do not overwhelm me: ask me only one or two questions at a time, and wait for my answer before you move on. First, reassure me and explain in plain words what is really going on. Then, if it matters, ask me which UK nation I am in (England, Wales, Scotland, or Northern Ireland), as the rules differ. Then gently gather what you need, one thing at a time: the amount; the period it covers; whether I had bills before; whether I sent meter readings; and whether the supplier made a mistake. Once you understand my situation, explain it to me simply, tell me what stage I am at and what it means, and tell me the single most important thing to do first and why. Then hold my hand through it: tell me exactly what to gather, write my dispute and any escalation to the Energy Ombudsman in full and ready to send, and explain clearly how and where to send it. Watch my deadlines at every step so I never miss one. Never tell me to just pay it, and never rush me. At the end of each step, give me a short plain-English summary of what we have done and the one thing to do next. I am acting for myself and I want to come out of this feeling calm and in control.

Keep the conversation open and save the documents Claude produces. That is all you need to start.

Before anything else

If your supplier is at fault, they cannot charge you for energy used more than twelve months ago.

A back bill arrives out of nowhere. Hundreds, sometimes thousands of pounds, for energy used long ago because the supplier never billed you properly, used estimates, ignored your readings, or set your direct debit too low. The shock is real and the instinct is to pay or to panic.

There is a rule on your side, built into every supplier's licence. It is called the back-billing principle, and it means that where the supplier was at fault, they cannot recover charges for energy used more than twelve months before the corrected bill. That can wipe out a large part of a surprise demand.

But there is an important honesty here: the rule protects against late or missing billing, not against a bill you did receive and simply did not pay. Knowing the difference is the whole game.

Your first move, two minutes
1
Photograph or save the back bill and any statement showing the dates it covers.
2
Open Claude at claude.ai, free on any phone.
3
Copy the prompt below and paste it into Claude: "I have had a surprise energy back bill and I want help. Act as my Energy Back-Billing Case Manager and help me calmly, one step at a time. Ask me only one or two questions at a time and wait for my answer. Start by reassuring me, then ask me which nation I am in, then gently ask me the amount, the period it covers, and whether I sent meter readings. Then explain to me in plain English what it is, what stage I am at, and exactly what to do first. Do not rush me, and never tell me to just pay it."
4
Read the plain answer, then find your country below.
Do not pay a large back bill on the spot to make it go away. People have paid, then reclaimed the money once they learned about this rule.

Choose your country. The rule applies across Great Britain through Ofgem. Northern Ireland has its own regulator.

Do it yourself

Work through it at your own pace, in plain English. Pick your country to begin.

Where do you live?

In England, Wales and Scotland, the back-billing principle is part of every supplier's licence, enforced by Ofgem. It applies to households and to microbusinesses. Where the supplier is at fault, charges for energy used more than twelve months before the corrected bill cannot be recovered.

The test is fault. If the supplier failed to bill you, billed on estimates while ignoring your readings, missed a fault you reported, or set your direct debit too low, the twelve-month limit bites. If you received accurate bills and did not pay, that is ordinary debt, not back-billing.

Click each stage to work out where you stand and what to do.

The Back-Billing Rule, England, Wales & Scotland
1

Work out if you are protected

It turns on supplier fault
Start here
▼  Check the test

The twelve-month limit applies where the shortfall is the supplier's fault. Run your situation against the recognised grounds.

  • They never billed you, though you asked, no accurate bill despite your requests.
  • They used estimates and ignored your readings, you provided figures and they billed on guesses anyway.
  • They missed information they held, a meter mix-up or a fault you reported that they failed to act on.
  • Your direct debit was set too low, and a shortfall built up that they did not address.
  • Where it does NOT apply, if you got accurate bills and did not pay, or you blocked meter access or readings, the protection is lost and they can pursue up to six years (five in Scotland by prescription).
Be honest with yourself. Ask Claude: "Here is my back bill situation: [describe]. Walk me through whether the Ofgem back-billing rule protects me, and which parts of the bill relate to energy used more than twelve months before the corrected bill."

Would you rather Claude just did this for you? That is the easy route, and usually the best one. Tap below to copy a ready-made message, paste it into a Claude chat at claude.ai, and Claude takes it from there, writing whatever you need to send.

New to Claude? It is free, here is how.
2

Get the breakdown and challenge it

Make them show the dates
Push back
▼  What to do

Ask the supplier for a full statement showing the periods covered, the readings used (estimated, actual, or smart), the unit rates, and any adjustments. Then mark everything that relates to energy used more than twelve months before the corrected bill and dispute that portion.

  • Request a full bill breakdown, dates, readings, rates, adjustments. Ask Claude to draft the request.
  • Identify the out-of-time portion, the charges older than twelve months. Ask Claude to help you isolate them.
  • Gather your proof of acting reasonably, screenshots of readings submitted, emails, complaint references, move-in date. Ask Claude what evidence strengthens your case.
  • Write the dispute, invoke the back-billing rule and ask them to remove the out-of-time charges. Ask Claude to draft it.
How to submit

Send your dispute to the supplier in writing, keep proof, and ask for their final response (a deadlock letter) if they refuse. Ask Claude to draft the letter.

Would you rather Claude just did this for you? That is the easy route, and usually the best one. Tap below to copy a ready-made message, paste it into a Claude chat at claude.ai, and Claude takes it from there, writing whatever you need to send.

New to Claude? It is free, here is how.
3

Escalate to the Energy Ombudsman

Free and binding on the supplier
Backstop
▼  What to do

If the supplier rejects your dispute or eight weeks pass without resolution, take it to the Energy Ombudsman, free of charge. Their decision binds the supplier. People have had whole out-of-time amounts removed and money refunded this way.

  • Get a deadlock letter or wait eight weeks, either opens the Ombudsman door. Ask Claude to request the deadlock letter.
  • Submit to the Energy Ombudsman, set out the back-billing breach and attach your evidence. Ask Claude to prepare the submission.
  • If you already paid, you can still reclaim out-of-time charges you should never have been billed. Ask Claude to help you claim a refund.
  • For the in-time portion you do owe, ask for an affordable payment plan. A back bill caused by supplier error should be spread generously. Ask Claude to propose terms.
Free help: Citizens Advice runs the consumer energy service. The Energy Ombudsman is free and independent. Ask Claude to draft each letter and write the letters.

Would you rather Claude just did this for you? That is the easy route, and usually the best one. Tap below to copy a ready-made message, paste it into a Claude chat at claude.ai, and Claude takes it from there, writing whatever you need to send.

New to Claude? It is free, here is how.

Northern Ireland has its own energy regulator, the Utility Regulator, and its own consumer body, the Consumer Council for Northern Ireland, rather than Ofgem and the Energy Ombudsman. The principle that you should not face unfair charges for a supplier's billing failure still applies, but the specific rules and the complaint route differ.

The fairness principle is similar, but do not rely on the exact Ofgem wording or the Energy Ombudsman route. In Northern Ireland the Consumer Council is your backstop.

Because the detail is NI-specific, verify the current position with the Consumer Council, or ask Claude to confirm the present rules. The practical steps below still hold.

Surprise Back Bills, Northern Ireland
1

Get the breakdown and dispute

Establish the supplier's fault
Start here
▼  What to do

As elsewhere, ask your NI supplier for a full breakdown of the back bill, establish whether the shortfall was their fault, and dispute charges that arose from their billing failure.

  • Request a full statement, dates, readings, rates. Ask Claude to draft the request.
  • Show you acted reasonably, readings sent, queries raised, access given. Ask Claude what evidence helps.
  • Dispute the unfair portion, ask Claude to draft the dispute, and to confirm the current NI back-billing position.
Free help in Northern Ireland: the Consumer Council for Northern Ireland handles energy complaints. Advice NI can help with any resulting debt.

Would you rather Claude just did this for you? That is the easy route, and usually the best one. Tap below to copy a ready-made message, paste it into a Claude chat at claude.ai, and Claude takes it from there, writing whatever you need to send.

New to Claude? It is free, here is how.
2

Escalate to the Consumer Council

The NI backstop
Backstop
▼  What to do

If the supplier will not put it right, escalate to the Consumer Council for Northern Ireland, which handles energy complaints in NI rather than the Energy Ombudsman used in Great Britain.

  • Complain formally first, get the supplier's final response. Ask Claude to draft it.
  • Escalate to the Consumer Council, they can investigate and press the supplier. Ask Claude to prepare the submission.
  • Arrange affordable payment for anything truly owed, ask Claude to propose terms.
How to submit

Complain to the supplier, then the Consumer Council for Northern Ireland. Ask Claude to draft each letter and write the letters.

Would you rather Claude just did this for you? That is the easy route, and usually the best one. Tap below to copy a ready-made message, paste it into a Claude chat at claude.ai, and Claude takes it from there, writing whatever you need to send.

New to Claude? It is free, here is how.

What the System Depends On

It depends on the bill looking unanswerable. A figure for energy you actually used feels impossible to argue with, so people pay catch-up bills that the rules say they never owed.

The rule is narrow and honest: it protects you when the supplier got the billing wrong, not when you simply did not pay. But where it applies, it can remove years of charges, and it works even after you have paid.

Do not panic-pay. Get the breakdown. Test it against the rule. Dispute, then escalate to the free regulator.

Know someone facing this? Send them this page. It is free, and no one should face it alone.