How to Complain About Your Energy Bill and Get a Refund (2026 Guide)

Energy bills in the UK have been a source of frustration for millions of households. Whether your supplier has overcharged you, applied incorrect tariff rates, failed to process a meter reading, or simply billed you for energy you did not use, you have strong legal protections that can help you get your money back. In this guide, we will walk you through the entire complaint process from start to finish, including the exact laws that protect you, how to escalate to the Energy Ombudsman, and a template complaint letter you can use today.

According to Ofgem data, energy suppliers paid out over £9 million in compensation to customers in 2025 alone. That is money returned to people who took the time to complain properly. If you believe your bill is wrong, the odds are genuinely in your favour.

Your Legal Rights When Disputing an Energy Bill

Before you pick up the phone or write a complaint, it is worth understanding the legal framework that protects you. UK energy consumers have some of the strongest protections in Europe, and knowing your rights gives you significant leverage.

The Consumer Rights Act 2015, Section 49

Section 49 of the Consumer Rights Act 2015 states that any service must be carried out with reasonable care and skill. Energy supply is a service, and if your supplier has billed you incorrectly, failed to apply agreed tariff rates, or not processed your meter readings properly, they have breached this duty. This gives you the right to a price reduction or, in many cases, a full refund of the overcharged amount.

Ofgem Supplier Licence Conditions

Every energy supplier operating in the UK must hold a licence from Ofgem, the energy regulator. These licences come with binding conditions. Under Standard Licence Condition 0, suppliers must treat customers fairly. Under SLC 21B, suppliers must produce bills that are accurate, transparent, and based on the best available data. If your supplier has sent you an estimated bill when they had access to actual meter readings, or if they have applied the wrong tariff, they are in breach of their licence conditions.

The Back-Billing Rules

One of the most powerful protections for energy customers is the Ofgem back-billing rule. If your supplier has undercharged you and only realised the mistake later, they cannot send you a bill for energy used more than 12 months ago. This is an absolute rule. It does not matter whether the error was yours or theirs. If they try to bill you for energy consumed more than a year in the past, you can refuse to pay that portion and cite Ofgem's back-billing principles. Note that this rule applies to domestic customers with standard credit or prepayment meters.

The Complaints Handling Standards

Ofgem requires all suppliers to have a clear, accessible complaints process. They must acknowledge your complaint promptly, provide a named contact or case reference number, and attempt to resolve the issue within 8 weeks. If they fail to resolve your complaint within 8 weeks, or if they send you a deadlock letter (stating they cannot resolve the issue), you can escalate directly to the Energy Ombudsman at no cost to yourself.

Step 1: Gather Your Evidence

Before you contact your supplier, spend 15 minutes gathering everything you need. Having your evidence ready makes the process significantly smoother and shows your supplier you are serious.

You will need your account number, the bill or bills you are disputing, your actual meter readings (take a photo with a timestamp), any previous bills that show different tariff rates or correct charges, records of any previous communication with your supplier, and bank statements showing what you have actually paid. If you use Paybacker to track your bills and subscriptions, you can pull all of this information from your dashboard in seconds, including historical payment data from your connected bank account.

Step 2: Contact Your Supplier Directly

Your first step is always to contact your energy supplier directly. Phone their customer service line or use their online complaint form. When you call, be clear about what is wrong, state the specific amount you believe you have been overcharged, and reference the bills in question. Ask for a case reference number and the name of the person handling your complaint. Take notes during the call, including the date, time, and what was discussed.

If you prefer to complain in writing (which creates a clear paper trail), send an email to their complaints department. Most suppliers list a specific complaints email address on their website. Writing gives you a documented record of exactly what you said and when you said it.

Step 3: Write a Formal Complaint Letter

If your initial contact does not resolve the issue, or if you prefer to start with a written complaint, a formal letter is your most powerful tool. Your letter should clearly state what has gone wrong, what resolution you expect, the legal basis for your complaint, and a reasonable deadline for response (typically 14 days).

Here is a template you can adapt:

Dear [Supplier Name] Complaints Department,

I am writing to formally complain about my energy bill for the period [dates]. My account number is [number].

The bill shows a charge of [amount], which I believe is incorrect for the following reasons: [explain specifically what is wrong].

Under Section 49 of the Consumer Rights Act 2015, energy supply services must be carried out with reasonable care and skill. The billing error described above represents a breach of this duty. Additionally, under your Ofgem licence conditions (SLC 21B), bills must be accurate and based on the best available data.

I am requesting [specific resolution: refund of X amount / bill recalculation / tariff correction] and expect a substantive response within 14 days of this letter.

If this matter is not resolved satisfactorily, I will escalate my complaint to the Energy Ombudsman.

Yours faithfully, [Your name]

Writing complaint letters can be time-consuming, which is why Paybacker's AI complaint generator creates professionally worded letters citing exact UK legislation in under 30 seconds. You simply enter your details and the AI does the rest.

Step 4: Escalate to the Energy Ombudsman

If your supplier has not resolved your complaint within 8 weeks, or if they have issued a deadlock letter, you have the right to escalate to the Energy Ombudsman. The Ombudsman is a free, independent service that investigates complaints and can make binding decisions on energy suppliers.

To escalate, visit the Energy Ombudsman website at energyombudsman.org and fill in their complaint form. You will need your case reference number from the supplier, copies of relevant correspondence, details of what resolution you are seeking, and evidence supporting your complaint. The Ombudsman can order your supplier to apologise, explain what went wrong, take corrective action, and pay financial awards including compensation. In 2025, the average financial award from the Energy Ombudsman was approximately £150, though awards can be significantly higher depending on the circumstances.

Step 5: Additional Escalation Options

If you are still not satisfied after the Ombudsman process, you have further options. You can report the supplier to Ofgem directly through their complaint form. While Ofgem does not resolve individual disputes, they use complaint data to identify suppliers who are consistently failing customers, which can lead to enforcement action. You can also take your case to the small claims court for amounts up to £10,000. This is a straightforward process that does not require a solicitor, and the filing fee is typically between £35 and £120 depending on the amount claimed.

Common Reasons Energy Bills Are Wrong

Understanding why your bill might be incorrect helps you identify the problem quickly and frame your complaint effectively.

Estimated Readings vs Actual Readings

If your supplier has been using estimated readings rather than actual meter readings, your bills may be significantly higher or lower than they should be. Always submit regular meter readings, or better yet, request a smart meter installation which sends readings automatically.

Tariff Errors

Sometimes suppliers apply the wrong tariff rate, particularly after a price change or when you have switched between tariffs. Check that your unit rate (pence per kWh) and standing charge match what was agreed in your contract.

Billing After Switching

If you have recently switched suppliers, you may receive a final bill from your old supplier. Check that this bill only covers energy used up to the switch date and uses actual meter readings taken on or near that date.

Direct Debit Miscalculations

Suppliers set your direct debit based on estimated annual usage. If this estimate is too high, you may be building up a credit balance. Under Ofgem rules, suppliers must review your direct debit at least once a year and adjust it if it is too high. You can request a refund of any credit balance at any time.

How Much Could You Get Back?

The amount you can recover depends on the nature of the error. Overcharges from incorrect tariff rates can run into hundreds of pounds. Estimated billing errors often range from £50 to £500 depending on how long the estimates were used. Back-billing disputes, where a supplier tries to charge you for energy used more than 12 months ago, can save you thousands. On top of the overcharged amount, you may also receive compensation for the inconvenience and time spent resolving the issue.

The average UK household could save £312 per year just by checking their bills and challenging errors. Paybacker scans your bank account and email inbox to find these overcharges automatically, so you do not have to do the detective work yourself.

Tips for a Successful Complaint

Keep everything in writing where possible. Verbal complaints are harder to prove later. Always note down the date, time, and name of anyone you speak to. Set calendar reminders for key deadlines, particularly the 8-week escalation window. Be firm but polite. Complaint handlers are more likely to go the extra mile for customers who are clear and reasonable. Include specific figures and dates rather than vague statements. Reference the relevant legislation by name, as this shows you know your rights and the supplier is more likely to take your complaint seriously.

Frequently Asked Questions

How long do I have to complain about an energy bill?

There is no strict time limit for complaining to your energy supplier. However, it is best to raise issues as soon as you notice them. For back-billing disputes, the key rule is that suppliers cannot bill you for energy used more than 12 months ago. For taking a case to small claims court, you have up to 6 years from the date of the issue.

Can my energy supplier cut off my supply if I dispute a bill?

No. Under Ofgem rules, your supplier cannot disconnect your energy supply while a complaint is being actively investigated. They also cannot disconnect vulnerable customers at any time. If a supplier threatens disconnection during a dispute, report this to Ofgem immediately.

What is the Energy Ombudsman and is it free?

The Energy Ombudsman is an independent, free service that resolves disputes between energy customers and suppliers. You can escalate to them after 8 weeks if your supplier has not resolved your complaint, or sooner if the supplier issues a deadlock letter. The Ombudsman can make binding decisions and order financial awards.

Do I need a solicitor to dispute my energy bill?

No. The entire complaints process, including escalation to the Energy Ombudsman and even small claims court, is designed to be accessible without legal representation. Tools like Paybacker can generate professional complaint letters citing exact UK legislation for you in seconds.

What evidence do I need to dispute an energy bill?

Gather your account number, the disputed bills, actual meter readings (preferably with timestamped photos), any previous correspondence with the supplier, and bank statements showing your payments. The stronger your evidence, the faster the resolution. Sign up for Paybacker to automatically track all your energy payments and spot billing errors before they cost you.