Sued for an unpaid utility bill in the UK, your defence options

You've received a court claim form from your energy supplier, water company, or a debt collector acting on their behalf. The letter says you owe £1,500 (or another amount) for unpaid bills dating back months or years. Your first instinct might be to panic or ignore it. Don't.

You have legal options. Many utility debt claims succeed not because the debt is real, but because defendants don't fight back. This guide walks you through the defences available to UK consumers, the regulators behind them, and the steps to take in the next 28 days.

The short version

If you've been sued for a utility bill:

1. Don't ignore the claim. You have 14 days to acknowledge service (form N9). Missing this deadline costs you the case by default.
2. Request detailed billing. Ask for every bill, meter reading, and estimated charge. Suppliers often can't produce them.
3. Check the age of the debt. If the oldest unpaid bill is older than 12 months (energy) or similar (water), you may have a back-billing defence.
4. Check if it's statute-barred. If the oldest bill is older than 6 years and you've made no payment in that time, the debt is legally unrecoverable.
5. File your defence (form N9B) within 28 days of receiving the claim. Include all evidence: meter disputes, billing errors, or the statute-barred argument.
6. Attend the hearing or settle. Most cases settle once you show evidence. If it goes to court, judges often rule in your favour if the supplier can't prove the debt is accurate and within back-billing limits.

At a glance

Who sues for utility debt

Original suppliers: Your energy company, water company, or telecoms provider will sometimes sue directly if your debt is recent (usually within 3 years) and significant (£1,000+).

Debt buyers: More often, the supplier has sold the debt to a third-party debt collection agency. These firms buy debt portfolios cheaply and sue to recover what they paid plus interest. They may not have the original billing records and rely on the supplier's data, which is often incomplete or estimated.

Debt buyers and your rights: Even if a debt buyer is suing, the underlying rules about back-billing and billing accuracy still apply. The debt buyer stands in the supplier's shoes legally but doesn't get special powers.

Step 1: Acknowledge service (N9) within 14 days

When you receive the claim form, check the "Response Pack" for form N9 (Acknowledgement of Service). Fill it out and return it to the court within 14 days of receiving the claim.

This single step keeps you in the game. If you don't acknowledge within 14 days, the claimant can ask the court for judgment by default. You lose the right to defend yourself, and a court order goes against you.

What to write: Keep it simple: "I acknowledge receipt of this claim and intend to defend it." You don't need to explain your defence yet.

Where to send: The court address is on the claim form (usually your local county court).

Step 2: Request meter readings and detailed billing

Before you write your defence, you need evidence. Write a letter to the claimant (the supplier or debt buyer) asking for:

• Every bill dated within the period of the claim (usually 3-5 years back)
• Every meter reading recorded against your account (actual and estimated)
• Proof that bills were sent to you (not just presumed)
• The date your account was opened
• Any payment history they hold
• Proof of any back-billing notice (if they're claiming you owe for old estimated bills)

How to send: Email or post to the address on the claim form. Ask for a response within 14 days. Keep a copy.

Why this matters: If the claimant can't produce meter readings or actual bills, their case is weak. Many suppliers lost old data when they switched IT systems. If the data is missing, you have grounds to argue the amount is not proven.

Defence route: Back-billing rule (the 12-month cap)

This is often the strongest defence for energy and water debts.

Energy (Electricity and Gas): The Standard Licence Conditions (SLC) and the Supplier Licence Condition Code of Practice state that a supplier cannot backdate bills for more than 12 months unless you have been deliberately obstructing a meter reading or tampering with a meter.

What this means:

• If you owe for estimated bills from more than 12 months ago, and the supplier didn't try to access your meter in that period, they can't recover those charges.
• If the claim includes charges from, say, January 2024 and it's now May 2026, those January 2024 charges are outside the 12-month window (if no meter access was attempted in 2024).

Water: Ofwat's rules on back-billing are similar. Charges older than 12 months are only recoverable if the water company can prove a valid reason (tampering, intentional obstruction, meter bypass).

In your defence: State that the claim includes charges older than 12 months for which no valid meter access was attempted. The claimant must prove otherwise.

Defence route: Meter or billing error

Meter disputes are common and often succeed.

What to argue:

• You believe your meter is faulty or under-reading.
• The bills are based on estimates rather than actual readings.
• You disputed the meter reading at the time and received no response.
• The amount charged does not match your typical usage (e.g., you've never used 10,000 kWh per quarter; your usage is normally 2,000).

How to support it:

• Compare bills month to month. Spot spikes and ask why. Meter faults often show as sudden jumps.
• Check your boiler installation date or recent home improvements. Did you have loft insulation added? That should lower gas bills.
• Request a meter test from the supplier (most are free under Ofgem rules). If the test shows under-reading, the claimant owes you a credit.
• Provide your own meter readings (from photos or a smart meter app) to show the claimant's figures are wrong.

In your defence: "The bills are based on erroneous meter readings. The claimant has not provided proof of actual meter access. I request the bills be recalculated based on actual readings [attach your evidence]."

Defence route: Statute-barred (6-year rule)

A utility bill debt becomes statute-barred (unrecoverable in court) if:

1. Six years have passed since the last bill (the limitation period starts from when the debt arose).
2. You have made no payment or acknowledgement of the debt in those six years.

If the oldest unpaid bill in the claim is dated before May 2020, and you haven't paid any part of it since then, the entire debt may be statute-barred as of now (May 2026).

Important caveat: The statute runs from each individual bill, not the total debt. If you have bills from 2020, 2021, 2022, etc., only the 2020 bills are statute-barred. The 2021 onwards bills are still recoverable.

In your defence: "The claimant cannot recover charges dating prior to [date 6 years ago]. No payment has been made on these charges since they were incurred. The debt is statute-barred under the Limitation Act 1980, Section 5."

Risk: Don't claim statute-barred lightly if you've made any payment in the past 6 years. Even a small payment restarts the clock.

Defence route: Identity fraud or wrong defendant

Less common, but real: you receive a bill or claim for an account you never opened or one fraudulently opened in your name.

What to check:

• Is the account in your name, address, and postcode?
• Did you receive the bills at the time? (If not, this is suspicious.)
• Can you prove you didn't live at that address during part of the claim period?
• Have you reported identity fraud to Action Fraud or your local police?

In your defence: "I did not open this account. The bills were not addressed to me or were received by an unauthorised party. I have reported this matter to [Action Fraud / Police] under case number [if applicable]. The debt cannot be recovered from me."

Defence route: Estimated bills and the right to actual readings

Energy suppliers must provide actual meter readings regularly. If your entire bill is estimated, this is a defence point.

Ofgem rules state:

• Suppliers must attempt to get actual readings at least once every two years for domestic customers.
• If a supplier issues estimated bills continuously without attempting a reading, it's a breach of licence conditions.

In your defence: "All bills in the claim period are estimated. The claimant has not provided evidence of attempting to access my meter for an actual reading. This is a breach of the Standard Licence Conditions. The charges are not proven and should be struck out."

Defence route: Vulnerability and Priority Services Register

If you are disabled, elderly, have a serious illness, or are a priority customer (on a heat or cold vulnerability register), the supplier owed you additional duties of care.

What this means for you:

• The supplier should have offered payment plans before taking court action.
• If you were on the Priority Services Register but weren't offered a plan, this is a breach.
• Even if the debt is real, the court may order a payment plan instead of judgment against you.

In your defence: "I am a priority customer [or disabled/elderly]. The claimant did not offer a payment plan before issuing these proceedings. Under Ofgem's Vulnerability Guidance, I was entitled to a reasonable arrangement. I offer to pay [£X per month], and request the court order this rather than judgment."

Step 3: File your defence (form N9B) within 28 days

You now have 28 days from receiving the claim to file your defence. This is a hard deadline. Submit it before day 29 or your defence is late (and the court may not accept it).

What to include in your defence:

1. A clear statement of which facts you deny (e.g., "I deny owing £1,500 for charges dating January 2024").
2. The legal route(s) you rely on (back-billing, statute-barred, billing error, etc.).
3. All evidence: meter readings, photos, correspondence with the supplier, payment history, proof of Priority Services Register status.
4. A clear conclusion: "The claim should be dismissed" or "The claim should be reduced to £X for charges within 12 months of service."

Form N9B: This is the "Defence and Counterclaim" form. You don't need to claim anything back (counterclaim), so leave that section blank. Focus on the defence.

Where to file: Post or email to the court address on the claim form. Email is usually faster. Keep a copy and proof of sending (email read receipt or postal certificate of posting).

Step 4: Mediation and small claims hearing

After you file your defence, the court will set a timetable:

Mediation: Many cases go to a free mediation session before trial. You and the claimant (or their solicitor) meet with a court mediator. Often the claimant will offer to drop the claim or reduce it once they see you have evidence.

If no settlement: The case proceeds to a small claims hearing (usually in person at the local county court or by video link). This is informal. You explain your defence; the claimant presents their case. The judge decides.

What the judge looks for:

• Can the claimant prove the debt is accurate and current? (If meter readings are missing, this fails.)
• Is the debt within the back-billing rules? (If it's over 12 months, the claimant must prove a valid exception.)
• Is the debt statute-barred? (If you haven't paid in 6 years, you win on this point alone.)
• Did the claimant breach their regulatory duties (e.g., no attempt to read your meter in 2 years)?

Most judges are sympathetic to consumers in utility cases because they see the pattern: suppliers issue vague claims, can't produce evidence, and rely on defendants not turning up.

Day to day (timeline)

Timings vary by court and workload. This is a typical pathway.

Common misconceptions

"If I don't pay the bill, I can't argue against the claim." Wrong. You can dispute the amount, the supplier's right to backdate it, or the accuracy of the meter. You don't have to pay to have a voice in court.

"Debt buyers have stronger claims than the original supplier." Wrong. Debt buyers stand in the supplier's shoes and are subject to the same rules about back-billing and evidence. They may actually have weaker claims because they often lack the full billing history.

"Estimated bills are always valid." Wrong. If the supplier hasn't attempted a meter reading in over two years and has issued only estimates, they've breached licence conditions. Estimated charges can be defended.

"I'm liable for bills even if I didn't receive them." Not necessarily. The supplier must prove bills were sent to you or that you were responsible for them. If your address changed and bills went to an old address, the supplier may not have valid proof of service.

"Statute-barred only applies if the debt is very old." True, but "very old" is only 6 years for utility debts. If you were sued today for charges from May 2020, those charges are now statute-barred (assuming no payment since then).

"I should pay something to show goodwill." Caution. Any payment restarts the statute-barred clock. Before paying, check with Citizens Advice or seek legal advice. A small "goodwill" payment can cost you a statute-barred defence.

Related concepts

• Defending a county court claim: the full process
• Statute-barred debts: when you don't have to pay
• Meter disputes and energy suppliers' duties
• Priority Services Register and vulnerability protections
• Ofgem enforcement and licence breaches
• Payment plans and hardship: alternatives to court
• Debt collection agency claims: your rights
• Small claims procedure and evidence in the UK

Sources

• Ofgem (2023). Standard Licence Conditions and Supplier Licence Condition Code of Practice. https://www.ofgem.gov.uk. Covers back-billing rules, meter access, and estimated charges for gas and electricity.
• Ofwat (2023). Water Company Charges Schemes and Customer Service Codes. https://www.ofwat.gov.uk. Sets back-billing and billing accuracy rules for water and sewerage companies.
• Citizens Advice (2024). Utility Bills and Debt. https://www.citizensadvice.org.uk. Practical guidance for consumers disputing utility bills and defending claims.

Disclaimer: This page provides information about UK utility debt claims and defences. It is not legal advice and does not create a solicitor-client relationship. For advice on your specific claim, contact Citizens Advice, your local law centre, or a solicitor. Court rules and procedures change; this information was current as of May 2026.

Written by Peter Kolomiets, founder of CaseCalm. UK content reviewed 2026-05-28.