How to Complain About Your Energy or Broadband Bill (UK 2026 Guide)

Last updated: June 2026

Millions of UK households receive inaccurate, inflated, or simply unexplained utility bills every year. Whether your energy supplier has hit you with a shock estimated bill, your broadband provider quietly raised your monthly price mid-contract, or a failed switch has left you being billed by two suppliers at once, you have clear rights — and clear routes to redress.

This guide explains the most common billing problems, the regulator rules that protect you, and the exact steps to take to get money back or put the situation right. It is practical information, not legal advice.

The Most Common Billing Problems

1. Estimated Bills and Catch-Up Charges

Suppliers are permitted to estimate your usage when they cannot access a meter reading. The problem arises when estimates run for months or years and are then corrected with a large "catch-up" bill. Under Ofgem's back-billing rule, energy suppliers cannot charge you for energy used more than 12 months before the bill was issued, provided the undercharge was not your fault (for example, you supplied readings when asked).

• Keep dated records of every meter reading you submit.
• If a catch-up bill covers a period older than 12 months, challenge it in writing immediately.
• Smart meters remove the estimation problem entirely — request one if you do not have one.

2. Direct Debit Set Too High

Suppliers have a legitimate interest in collecting enough to cover your annual usage, but Ofgem guidance requires that direct debits be set at a "reasonable" level. If your account has built up a large credit balance, you are entitled to ask for a refund. Suppliers must respond to a refund request within a reasonable timeframe and cannot simply refuse without explanation.

• Check your online account regularly for credit accumulation.
• Request a refund in writing if your credit exceeds roughly two months of bills.
• If the supplier refuses, this is a formal complaint trigger.

3. Failed Energy Switches

Ofgem's switching guarantee means a domestic energy switch must complete within five working days (faster under the "next-day switching" rollout now under way). When switches fail, customers can end up billed by both the old and new supplier, or find themselves on an expensive out-of-contract tariff while the switch sits in limbo.

• The gaining supplier is responsible for managing the switch process.
• Document every confirmation email and reference number.
• If you are billed twice for the same period, write to both suppliers immediately and copy in the evidence.

4. Broadband Mid-Contract Price Rises

From January 2024, Ofcom rules require broadband and phone providers to state the exact cash value of any future price rises at the point of sale — not just a vague reference to inflation. If your provider raises prices by more than the amount disclosed at sign-up, you have the right to exit your contract penalty-free. This applies even if the contract still has months to run.

• Check your original contract or order confirmation for the exact price-rise clause.
• If the increase exceeds what was disclosed, notify the provider in writing and exercise your right to leave.
• The right to exit must be exercised within 30 days of receiving notice of the price rise.

5. Broadband Slow Speeds and Service Failures

Ofcom's Automatic Compensation scheme (which covers BT, Sky, TalkTalk, Virgin Media, Zen Internet, and others) gives you a right to automatic payments when:

• Your service is not repaired within two full working days of a reported fault (currently £9.76 per day).
• An engineer fails to turn up for a scheduled appointment (£30.49 per missed appointment).
• Your new service is delayed beyond the promised start date (£6.10 per day of delay).

Compensation under this scheme should be applied automatically. If your provider is in the scheme and has not credited you, this is a formal billing complaint. Providers not in the Automatic Compensation scheme still owe you a remedy under their own terms of service and Ofcom's general conditions.

Your Rights at a Glance

Understanding which regulator covers which problem saves time:

• Energy (gas and electricity): Regulated by Ofgem. Complaints escalate to the Energy Ombudsman, which can require suppliers to apologise, correct bills, and pay compensation.
• Broadband, landline, and mobile: Regulated by Ofcom. Complaints escalate to either the Communications Ombudsman or CISAS (both are Ofcom-approved ADR schemes). You can check which scheme your provider belongs to on the Ofcom website.
• Right to exit on price rises (broadband/phone): Ofcom rules introduced January 2024. The right is automatic if the provider raised prices above what was contractually disclosed.
• Direct debit refunds (energy): Covered by Ofgem's supplier licence conditions. Suppliers must repay credit balances on request within a reasonable period.

Evidence to Gather Before You Complain

A well-evidenced complaint is resolved faster and is more likely to succeed at Ombudsman level. Collect the following before you contact your supplier:

• All bills for the period in question (paper or PDF).
• Meter readings with dates — photographs of the meter display work well.
• Your original contract, tariff confirmation, or order summary.
• Any correspondence (emails, letters, live-chat transcripts) with the supplier.
• Bank statements showing the direct debit amounts actually taken.
• For failed switches: confirmation emails from both suppliers and any MPAN / MPRN reference numbers.
• For broadband faults: fault reference numbers, engineer appointment confirmations, and speed test results (use Ofcom's own speed checker tool for evidential weight).

If you believe your billing dispute has caused you quantifiable financial loss — for example, you paid a debt collector for a charge that was later found to be incorrect, or you incurred costs switching provider — document those amounts carefully. The Ombudsman can award compensation for financial loss as well as for distress and inconvenience.

Struggling to make sense of a complex billing dispute? Our team can review your case and help identify the strongest grounds for complaint. See our energy billing claims service for details.

Step-by-Step Complaint Process

Step 1 — Complain to Your Supplier Formally

Contact the supplier's complaints team (not general customer service) in writing — email is fine. State clearly:

1. What the problem is and when it started.
2. What you want them to do (correct the bill, refund the credit, pay Automatic Compensation, release you from contract, etc.).
3. That this is a formal complaint and you expect a response within eight weeks.

Keep a copy of everything you send. Suppliers are required by their licence conditions to acknowledge complaints and to attempt resolution.

Step 2 — Wait for the Eight-Week Deadline (or a Deadlock Letter)

Ofgem and Ofcom both require that suppliers attempt to resolve complaints within eight weeks. If eight weeks pass without a satisfactory outcome, or if the supplier writes to say it cannot resolve the complaint (a "deadlock" letter), you can immediately escalate to the relevant Ombudsman.

Step 3 — Escalate to the Energy Ombudsman or Communications Ombudsman / CISAS

Both schemes are free for consumers. You submit your complaint online, attach your evidence, and the Ombudsman investigates independently. The process typically takes eight to twelve weeks.

• Energy Ombudsman: Covers gas and electricity suppliers regulated by Ofgem. Awards can include bill corrections, refunds, and financial compensation.
• Communications Ombudsman: Covers broadband, landline, and mobile providers that are members of the scheme (check the Ofcom website for a current list).
• CISAS: The alternative ADR scheme for communications providers not in the Communications Ombudsman scheme.

Ombudsman decisions are binding on the supplier if you accept the outcome. You are free to reject the decision and pursue other routes if you are not satisfied, but the supplier cannot ignore an accepted award.

Step 4 — Consider a Formal Resolution Letter

If your complaint involves a significant sum — for example, a large back-bill, a disputed direct debit spanning several years, or a broadband exit fee charged unlawfully — a professionally drafted resolution letter can materially strengthen your position before or alongside the Ombudsman process. A good letter cites the specific regulatory provisions, sets out your financial loss, and makes clear that you are aware of your escalation options.

Frequently Asked Questions

My energy bill is estimated — can I just refuse to pay it?

No. Refusing to pay can affect your credit file and lead to debt recovery action. Instead, submit an actual meter reading, ask the supplier to re-bill based on it, and dispute any portion of the bill that falls outside the 12-month back-billing limit. Pay what you accept as correct while the dispute is ongoing and note this clearly in writing.

My broadband provider raised prices mid-contract. Can I leave for free?

Yes, provided the increase exceeds what was disclosed in your original contract under Ofcom's January 2024 rules. You must give notice within 30 days of being notified of the price rise. If the provider tries to charge an early termination fee, challenge it formally and escalate to the Communications Ombudsman or CISAS if necessary.

How much can the Energy Ombudsman award?

The Energy Ombudsman can direct suppliers to correct bills, provide refunds, pay compensation for distress and inconvenience (commonly up to £150 for straightforward cases, more for severe cases), and make goodwill payments. There is no fixed cap, but awards reflect the seriousness of the failing and the impact on the consumer.

My supplier has gone into administration. What happens to my complaint?

Ofgem will appoint a Supplier of Last Resort to take over your account. Your existing complaint can still be referred to the Energy Ombudsman. If compensation has already been awarded and the supplier has not paid it, contact the Energy Ombudsman for guidance on enforcement.

Can I complain about a bill from more than a year ago?

For energy, the 12-month back-billing rule limits what suppliers can charge you, but you can still complain about a dispute that arose more than a year ago if the underlying problem is ongoing. For broadband, standard contract law limitation periods apply, but most ADR schemes will not accept complaints about events more than nine to twelve months old — check the relevant scheme's rules before submitting.

Take Action Now

Billing disputes do not resolve themselves. The longer an estimated bill or an inflated direct debit goes unchallenged, the harder it becomes to obtain a full remedy — especially once a 12-month back-billing window closes.

If you have a dispute you are struggling to move forward, our energy and broadband billing claims service can help you put the right arguments in front of the right people, quickly.

Start your free case assessment now →