Do I Have to Pay for Energy That I Used Over a Year Ago?

In today’s climate of rising household costs, few things are more unsettling than receiving an unexpected energy bill — especially one that covers gas or electricity used over a year ago. For many UK households, this kind of surprise charge is not only frustrating, it can feel deeply unfair.

These delayed charges, known as backbilling, have become increasingly common in recent years, often caused by issues such as estimated readings, billing errors, or suppliers struggling to keep up with account updates. But here’s what many people don’t realise: you might not have to pay.

Thanks to regulations set out by the energy watchdog Ofgem, most domestic energy customers are protected from being charged for energy usage older than 12 months — as long as the delay in billing wasn't your fault. That means if your supplier failed to send you a bill or didn’t ask for a meter reading, you may have the right to challenge the charge.

This article will explain exactly what backbilling is, how the rules protect you, and what steps to take if you receive a bill for long-past usage. We’ll also share ways to avoid issues in future, and help you save on everyday costs — not just energy — by making smart use of voucher codes that stretch your budget further.

And, when you save with us, you’re also helping others. At My Favourite Voucher Codes, every purchase made through our site contributes to UK charities — giving you another reason to feel good about spending wisely.

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What Is Backbilling?

Backbilling is when your energy supplier sends you a bill for gas or electricity you used in the past but weren’t charged for at the time. This might cover a few months of usage, or in some cases, more than a year — often leaving people surprised, confused, and concerned about whether they’re really obliged to pay.

These bills usually arise because of delays or mistakes on the supplier’s side. Common reasons include missed meter readings, estimated usage being corrected later, or system errors where bills were never generated or sent. Sometimes, it can also happen when a new supplier takes over and identifies an issue that was overlooked previously.

With more energy companies facing operational challenges, cases like this have become more common. Billing systems are under pressure, and not all households have smart meters that regularly send data. As a result, suppliers may only discover discrepancies after many months — prompting a large, backdated charge.

While this might feel like a personal mistake, in most cases, it's not the customer who's at fault. That’s exactly why protections exist — and why understanding the rules around backbilling is so important. If a bill lands on your doorstep for energy used a year or more ago, it’s worth checking whether you actually need to pay it at all.

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Your Rights: Ofgem's 12-Month Rule

If you've received a bill for energy used more than a year ago, you're not alone — and crucially, you may not have to pay it. Since 2018, energy customers in the UK have been protected by the Ofgem backbilling rules, which prevent suppliers from charging for gas or electricity used over 12 months ago, provided the delay was not your fault.

This means that if your supplier failed to bill you correctly, didn’t ask for meter readings, or issued estimated bills without later correcting them in time, they cannot legally demand payment for energy used more than a year before the date of the accurate bill.

The rule applies to both gas and electricity, and is designed to protect domestic customers from being penalised for supplier errors or delayed billing. It covers most standard energy contracts and applies whether you're with a large supplier or a smaller one.

MoneySavingExpert’s Martin Lewis recently reinforced this message, urging consumers not to automatically pay backdated bills without questioning them. As he pointed out, if you’ve been doing your part — such as providing meter readings when asked and paying regular bills — you are entitled to challenge charges that fall outside the permitted timeframe.

That said, it’s important to act promptly. If you receive a backdated bill, check the dates and contact your supplier to raise the issue under the 12-month rule. You can also refer to Ofgem’s published guidance or escalate to the Energy Ombudsman if your case isn’t resolved fairly.

Knowing your rights can make all the difference — and prevent you from paying a bill that shouldn't have landed on your doorstep in the first place.

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When You Might Still Have to Pay

While Ofgem’s 12-month backbilling rule offers strong protection for most domestic energy customers, there are some important exceptions where a supplier may still be within their rights to bill you for older energy usage.

The key distinction lies in who was responsible for the delay. If the supplier was at fault — for example, by failing to send bills or request meter readings — then the rule protects you. However, if the delay occurred because of something on your side, the protection may not apply.

You might still have to pay if:

• You deliberately avoided giving access to your meter — for example, by refusing to allow a meter reading or blocking entry over a long period.

• You ignored repeated requests for accurate readings, or failed to respond to your supplier’s attempts to contact you.

• You gave false information or otherwise acted dishonestly in relation to your account.

In these cases, the supplier can argue that they made reasonable efforts to bill you correctly but were prevented from doing so. As a result, they may be entitled to issue a backdated charge, even if it covers energy used over a year ago.

However, this doesn’t mean you should accept the bill without question. If you're unsure whether you're liable, it's worth asking your supplier to explain why the bill was issued and whether the 12-month rule was considered. You can also dispute the charge and escalate the complaint if needed.

The bottom line? Most customers who have acted in good faith are protected — but it’s important to understand the full picture before making a payment you may not owe.

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What to Do if You Receive a Backdated Bill

Receiving a backdated bill — particularly one demanding payment for energy used over a year ago — can be alarming. But before you reach for your bank card, it’s important to take a moment, assess the situation, and understand your rights.

Here’s what you should do:

1. Check the Dates on the Bill

Carefully review the billing period. Is the supplier asking you to pay for energy used more than 12 months ago? Make a note of any charges that relate to usage outside that one-year window.

2. Review Your Account History

Look through your previous bills, emails, or meter readings. Have you been regularly paying what you owed? Have you submitted readings when requested? If so, and you haven’t missed any key communications, it strengthens your case under the 12-month rule.

3. Contact Your Supplier

Reach out to your supplier as soon as possible and reference Ofgem’s 12-month backbilling rule. Ask for a detailed breakdown of the charges and request a written explanation as to why the bill has been issued now.

You can say something like:

“I understand Ofgem rules state I may not be liable for energy used over 12 months ago if the delay in billing was not my fault. Can you confirm whether this bill complies with that regulation?”

4. Make a Formal Complaint if Needed

If your supplier refuses to cancel the charge or doesn’t respond, follow their complaints process. Keep all communication in writing and make sure you ask for your case to be escalated.

5. Escalate to the Energy Ombudsman

If your complaint isn’t resolved after eight weeks (or earlier if the supplier issues a deadlock letter), you can take your case to the Energy Ombudsman. They can review the matter independently and may order the supplier to cancel the bill if it breaches Ofgem’s rules.

6. Don’t Ignore It — But Don’t Panic Either

Unresolved bills can potentially lead to credit issues or collection notices, so don’t leave it untouched. At the same time, don’t rush to pay without checking whether you actually owe the money.

Taking prompt, informed action gives you the best chance of resolving the situation fairly — and possibly avoiding a significant, unexpected cost.

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Tips to Avoid Backbilling in Future

While backbilling often isn’t the fault of the customer, there are simple steps you can take to reduce the chances of it happening — or at the very least, to spot any issues early before they escalate into large, unexpected bills.

1. Submit Regular Meter Readings

If you don’t have a smart meter, make it a habit to submit your own readings monthly. This helps your supplier issue accurate bills based on your actual usage, rather than relying on estimates. Some suppliers offer reminders via email or app notifications, which can make this even easier.

2. Check Your Bills Carefully

Set aside a few minutes each month to check your energy bill. Look at the meter readings used, the billing period, and whether charges are based on actual readings (“A” or “C”) or estimates (“E”). Spotting discrepancies early can help you raise any issues before they turn into larger problems.

3. Keep Your Contact Details Up to Date

Ensure your energy supplier has your current email, phone number and address. If they can’t get in touch with you, they may stop sending bills or miss chances to resolve problems early on.

4. Make Use of Online Accounts or Supplier Apps

Most energy companies now offer online portals or apps where you can view your balance, check usage and submit readings. These tools help you stay in control and flag up anything unusual quickly.

5. Consider a Smart Meter

A smart meter sends automatic readings to your supplier, helping to eliminate estimated billing altogether. It can also give you real-time insight into how much energy you're using, which is useful for budgeting and reducing waste.

6. Keep Records

Hold on to your bills and any emails or letters from your supplier — especially those relating to meter readings or billing issues. If a problem arises later, having clear documentation puts you in a much stronger position to resolve it.

By staying informed and engaged with your energy account, you can minimise the risk of unexpected bills and avoid the stress that backbilling can bring. It’s all part of managing your household finances with confidence.

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How to Cut Down Energy Costs

Even if your energy billing is in order, the cost of gas and electricity can still take up a large share of your monthly budget — especially during colder months. The good news is that small, consistent changes in your habits and home can lead to meaningful savings.

1. Make Simple Behavioural Changes

Switching off appliances at the wall, turning off lights when leaving a room, and lowering your thermostat by just one degree can all have a noticeable impact. Reducing tumble dryer use, taking shorter showers, and only boiling the water you need are easy ways to cut usage without major lifestyle changes.

2. Use Energy-Efficient Appliances

Where possible, opt for appliances with a high energy efficiency rating (such as A+++). While the upfront cost may be higher, they use significantly less power over time — which reduces both your bills and your environmental footprint.

3. Draught-Proof Your Home

Simple DIY solutions like fitting draught excluders, sealing gaps around windows and doors, or adding insulation to your loft can help retain heat and reduce the need for constant heating.

4. Monitor Your Usage

A smart meter or energy monitor can help you understand where your energy is going. By seeing your usage in real time, you can spot which appliances are the most power-hungry and adjust your habits accordingly.

5. Check for Support Schemes

Some households may be eligible for schemes like the Warm Home Discount, Winter Fuel Payment, or Cold Weather Payment. These government-backed initiatives can provide financial support to help cover heating costs during colder periods.

6. Be Proactive About Your Tariff

If you're not on a fixed tariff, it’s worth checking what you’re paying per unit and comparing it with other available deals. While options have been more limited in recent years, it’s still worth reviewing your plan when things stabilise.

Energy-saving doesn’t mean going without — it means using what you need more efficiently and being aware of where your money is going. And as we’ll explore next, these same principles apply to everyday spending, where smart use of voucher codes can help you save even more.

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Save on More Than Just Energy: Use Voucher Codes for Everyday Essentials

Managing household bills doesn’t stop with energy. From the weekly food shop to clothing, school supplies, and home essentials, everyday costs add up quickly — especially when budgets are tight. One of the simplest and most effective ways to ease that pressure is by using voucher codes.

At My Favourite Voucher Codes, we make it easy to find genuine, up-to-date discounts for a wide range of well-known UK retailers. Whether you’re stocking up on groceries, replacing appliances, or shopping for seasonal sales, using a voucher code at checkout can lead to significant savings with just a few clicks.

But the benefits go beyond the immediate discount. When you get into the habit of using voucher codes as part of your normal online shopping routine, you can save consistently across the year — helping you stretch your income further and free up cash for the things that really matter.

Our platform is designed with ease of use in mind — no pop-ups, no gimmicks, and no wasted time. Just trusted offers you can rely on, regularly updated and carefully selected to help UK households spend less on the things they already buy.

It’s about making small changes that make a real difference — and as we’ll explain next, every time you save with us, you’re also supporting important causes across the country.

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You Save, We Give: How Your Savings Help UK Charities

At My Favourite Voucher Codes, saving money isn’t just about helping your own household — it’s also about giving back. Every time you use one of our voucher codes, you’re not only reducing your spending, you’re also supporting charities across the UK.

Here’s how it works: each month, we donate 20% of our profits to a UK charity, and we let our users choose where that money goes. Visitors to the site can vote for one of four nominated charities, and at the end of the month, the organisation with the most votes receives the donation. It’s a simple model, but one that makes a real difference.

Over the years, our community has helped raise thousands of pounds for a wide range of causes — from mental health support services and children’s charities to environmental organisations and homelessness outreach. Whether you’re saving on a supermarket shop or picking up a gift online, your everyday purchases are helping others in need.

This approach allows our users to make thoughtful, ethical choices without spending any extra money. You're already shopping online — why not do it in a way that benefits both your budget and the wider community?

It’s just one more reason why so many people return to My Favourite Voucher Codes again and again: because when you save with us, you’re also helping someone else.

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Final Thoughts: Know Your Rights and Take Control

Navigating energy bills can be stressful, especially when unexpected charges appear. But the key takeaway is this: you have rights, and you don’t have to accept every bill without question — particularly when it comes to energy used more than a year ago.

Ofgem’s 12-month backbilling rule exists to protect consumers like you from being penalised for supplier errors. If you’ve done your part — by paying bills, responding to requests, and keeping your account in order — then you shouldn’t be held responsible for their delay. And if a supplier does try to charge you unfairly, there are clear steps you can take to challenge it and seek a fair outcome.

Alongside understanding your energy rights, it’s also worth exploring how small changes can reduce pressure on your household budget. From regular meter readings to smarter shopping habits, every little action adds up — especially when you use tools like My Favourite Voucher Codes to save on everyday essentials.

And while you’re saving, you’re also supporting others. Every voucher code used on our site contributes to charitable donations that help causes across the UK — proof that making better financial decisions can have a positive ripple effect beyond your own home.

Knowledge is power — and in this case, it can save you both stress and money. So take control, stay informed, and don’t be afraid to question the bills that don’t feel right.

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by Julian House 31st March 2025

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Citation Links and Resources

1. Ofgem – Backbilling Rules and Consumer Rights
   Ofgem is the UK’s energy regulator and provides full details on the 12-month backbilling protection rule.
   Ofgem

2. Energy Ombudsman – How to Make a Complaint
   If a customer’s complaint isn’t resolved by their energy supplier, they can escalate it here.
   energy ombudsman

3. MoneySavingExpert – Martin Lewis on Energy Backbilling (March 2025)
   Martin Lewis explains the 12-month rule and what to do if you receive a bill for energy used over a year ago.
   Money Saving Expert

4. Citizens Advice – Problems with Energy Bills
   Useful for additional support if customers are facing billing issues or need help understanding what to do.
   Citizens Advice

5. GOV.UK – Help with Heating Costs
   Covers schemes such as the Warm Home Discount, Cold Weather Payment, and Winter Fuel Payment.
   Gov.UK

6. Smart Energy GB – Benefits of Smart Meters
   Information about smart meters, including how they help avoid estimated bills.
   Smart Energy GB

7. My Favourite Voucher Codes – About Us / Charity Donations
   For readers who want to learn more about how the site supports charities through voucher code use.
   My Favourite Voucher Codes