How to Top Up a Prepayment Meter and Use Emergency Credit

A prepayment meter means you pay for gas or electricity before you use it, rather than receiving a bill afterwards¹. You load credit onto a key, card or smart meter, and the meter deducts the cost of what you use, plus a daily standing charge, from that balance. Once the credit runs out, no energy can be used until you top up again².

There are two broad systems in the UK. Traditional prepayment meters use a key or smart card that you charge with money at a shop, then insert into the meter³. Smart meters in prepayment mode can be topped up online, by phone, by text or through an app, with the credit sent to the meter remotely⁴. In Northern Ireland, most prepayment homes use a Keypad meter, which works differently again: you buy a code and type it into the keypad⁵.

Prepaying for your energy and how it works in practice

A prepayment meter is exactly what the name suggests: a meter that requires payment before energy is used, on a pay-as-you-go basis⁸. Ofgem describes it as a way to pay for electricity or gas in advance rather than after you have used it¹. Instead of a bill arriving monthly or quarterly, you buy credit first and the meter draws it down as your home consumes energy.

Day to day, that means watching a balance rather than opening a bill. A traditional prepayment meter displays the remaining credit on the meter itself, and a smart meter in prepayment mode shows the balance on its screen, so the household can see how close it is to running out. Because the meter records what you pay, your supplier does not need to read it in the usual way, and you top up when you run out of energy rather than paying by Direct Debit⁹.

The trade-off is worth understanding from the start. Prepayment meters are generally more expensive to run than credit meters, can be difficult to switch away from, and can leave you without electricity if you do not keep the meter sufficiently topped up¹⁰. The supply is conditional: as nidirect puts it for Northern Ireland, "you'll only get a supply when it's topped up"¹¹. For a household's energy independence, prepayment gives control over when and how much you pay, but it also means the supply depends on you acting before the money runs out.

How to add credit: in person, by key or card, app or code

How you top up depends on which meter you have. Almost all traditional prepayment meters use either a key or a smart card, charged at an official PayPoint or Payzone outlet³. Ofgem confirms the same routes: a local PayPoint store or Post Office, using the meter's key or card². nidirect lists the same outlets, including newsagents and Post Offices¹¹.

A smart meter in prepayment mode changes what is technically possible. Ofgem's guidance is that with a smart prepayment meter a household may be able to top up online or using the supplier's mobile app². Smart Energy GB describes the range the technology enables: prepay customers can top up "in a number of ways, which could include online, via telephone or text message, or even with a smartphone app - no gas card or electricity key necessary"⁴. The government's statement of consumer rights is that top-up must be available in a way that suits each household, whether in person or remotely¹².

• In person: at a PayPoint, Payzone or Post Office, with a key or card for a traditional meter, or a barcode for a smart meter²
• Online or by app: through your supplier's website or app, for smart prepay meters²
• By phone or text: where your supplier offers it⁴
• By code: buying a code and entering it into the meter, the standard method for Northern Ireland Keypads⁵

Once a smart prepay meter has been topped up, the credit should appear on the meter within 1 hour³. Cash payment at a shop remains available with a smart meter as well: the supplier gives the household a way to do that, for example a barcode, card or reference number to give to the shop¹³.

Adding credit to a Keypad meter in Northern Ireland

Northern Ireland's prepayment system is different from Great Britain's. Most prepayment customers there have a Keypad meter, which takes a numbered code typed directly into the unit rather than a charged card. Power NI, the main Keypad supplier, allows online top-ups without any card at all: "If you've lost your keypad card, don't worry, you don't need your Keypad card to top-up"⁵.

To top up online, you need your 19-digit Keypad Premise Number (KPRN), which usually begins with 9826908501, and your postcode. No registration is required, so a family member or neighbour can top up on your behalf with those two details⁵. Registering an online account brings extras: saved payment details, a record of previous top-up codes and letters, and access to the Power NI Perks rewards scheme⁵.

If you need a replacement card, Power NI posts one out, but the company asks you to allow up to 3 weeks for delivery⁵. That gap matters less than it would elsewhere, because the card is not needed to top up.

The Keypad comes in more than one type. Northern Ireland Networks' metering guidance lists a single-rate 1E Standard Keypad Meter for an ordinary house or apartment with a prepayment meter, and a 3E keypad meter with Economy 7 for heating and water storage heating¹⁴. If you are unsure which meter you have, the billing method tells you: "If you pay by top-up then it will be a keypad meter. If you receive a monthly or quarterly bill from your supplier, then it will be a credit meter"¹⁵.

Typing in a top-up code yourself

When a top-up cannot reach the meter automatically, you enter it by hand. With a smart meter, if the remote top-up does not arrive, "you can add the top-up manually using a 20-digit code also known as your Unique Transaction Reference Number ([UTRN)] which you'll find on your receipt/payment confirmation"¹⁶. The same principle applies to Keypad meters, where the code is the whole system.

The practical points are simple. Type the code carefully, digit by digit, checking against the receipt or payment confirmation before you press accept. If the code is rejected, re-check each digit before trying again: the most common causes are a mistyped digit, a code already used, or a code issued against a different meter. If the code is correct but the meter still refuses it, contact your supplier; they can confirm whether the payment registered on their side.

Allow time for the credit to show. With a smart prepay meter, credit should appear within 1 hour of topping up³. Do not assume a rejection has lost your money: the payment and the meter are two systems, and the supplier can reconcile them.

One scheme worth knowing about operated on vouchers. Under the UK Government's Energy Bill Support Scheme, prepayment customers received smart meter credits or payment vouchers for traditional prepay meters, providing top-ups for their meters¹⁷. People using prepayment meters were in some cases required to redeem those vouchers at their local top-up point¹⁸. The scheme has ended, but it shows the pattern: support aimed at prepayment households often arrives as a voucher or code that you redeem yourself.

Emergency credit: a small borrowing facility, not a gift

Emergency credit is a small buffer that keeps the supply on after your regular credit runs out. The Centre for Sustainable Energy describes it as "a small amount of emergency credit which is designed to maintain your energy supply" once your balance hits zero, reclaimed from your next top-up³. Uswitch's comparison is the clearest: "Most prepayment meters have an emergency credit budget you can use, like an overdraft, but it is limited"⁷.

The typical amount is around £10¹⁹. Age UK's guidance is that "your supplier should offer you emergency credit wherever possible"²⁰. With a smart prepay meter there is usually an emergency credit button that can be pressed if extra time is needed before a top-up is possible²¹.

How it is paid back is the part to plan for. Scope's guidance is blunt: "You will have to pay for the credit you use"²². Emergency credit and friendly credit usually need to be repaid in full before you can use them again²³. In practice that means your next top-up first clears the emergency credit, and only the remainder becomes usable balance. If you activate £10 of emergency credit and then top up £15, expect £10 of that to disappear immediately.

Friendly credit: cover through the night and festive periods

Friendly credit is the companion to emergency credit, and it answers a specific fear: the supply cutting out at night, at the weekend or over a holiday, when shops are shut and topping up is hard or impossible. Where a supplier operates friendly credit, the meter does not disconnect when the balance reaches zero during the protected period; instead the debt is recorded and collected from your next top-up.

The repayment rule is the same as for emergency credit. Smart Energy GB's guidance for customers worried about energy bills states that "Emergency credit and friendly credit usually need to be repaid in full before you can use them again"²³. So friendly credit is not free energy either: it is a timing protection, shifting the moment of disconnection to a point when you can actually get to a shop or an app.

The underlying rule it protects against is absolute. Ofgem's prepayment guidance states: "Once your credit runs out you will not be able to use any energy until you top up again"². Friendly credit softens when that rule bites, not whether it applies.

Whether you get friendly credit, and during which hours, depends on your supplier and tariff, so check your supplier's terms rather than assuming. What is consistent across the guidance is the design intent: prepayment systems build in buffers, emergency credit and friendly credit, precisely because a hard cut-off with no warning period would be dangerous. The Energy Bill Support Scheme's treatment of prepayment customers, delivering credits or vouchers to top up meters¹⁷, reflected the same recognition that prepayment households have no bill in which a payment can quietly appear.

What the screen shows: credit, debt and daily charge

The display is where a prepayment household manages its energy, so it is worth learning what it shows. With a smart meter in prepay mode, the in-home display is the main window onto the account, showing the balance for each fuel and how close it is to running out. That balance view, alongside how quickly credit is falling, is the practical budgeting tool.

On a Keypad meter in Northern Ireland, the meter itself carries the display and the buttons. The meter type determines what appears: a single-rate 1E Standard Keypad Meter serves an ordinary house or apartment, while a 3E keypad meter with Economy 7 covers heating and water storage heating, and will show rate information accordingly¹⁴. Short codes and messages on the display relate to the meter's status, and their meaning varies by model and situation, so Power NI support can tell you what a particular display is showing⁵.

What to check regularly:

• Any debt figure shown on the meter, which explains a shrinking balance²⁴
• The daily standing charge, which continues to accrue even when no energy is used²⁴

If the display shows no credit after a top-up that the supplier confirms went through, wait up to an hour before assuming failure³. If there is a genuine fault, the supplier should confirm the problem and offer a solution, either fixing the meter remotely or replacing it²⁴.

Why your credit does not stretch as far as you think

This is the question that catches most prepayment households out: money goes in, but the balance rises by less, or the credit vanishes faster than the heating seems to justify. Two mechanisms explain almost all of it: standing charges and debt repayment.

Standing charges are daily, fixed charges that apply whether or not you use any energy. The Centre for Sustainable Energy's guidance on prepayment debt is explicit about the trap: "If you don't top up your meter (for example, your gas over summer), this daily standing charge will start to build as a debt, and top-ups may be used to pay off previous weeks' unpaid daily standing charges"²⁴. A household that leaves the gas meter untouched all summer can return in autumn to find the first top-up swallowed by months of accrued standing charge.

Debt repayment works in two main ways, and CSE gives a worked example of each. If the debt repayment is set at £6 a week and you top up £10 a week, £6 goes towards the debt and £4 is added as credit; missed payments are added up and deducted from the next top-up. If the repayment is set at 30%, every £10 top-up means £3 towards the debt and £7 as credit²⁴.

Debt can arrive on the meter from several directions. You can owe money if you have used emergency credit, missed a standing charge payment, or are on a repayment plan⁷. Debt from a previous credit meter account may also have been transferred onto the prepayment meter by the energy company, with automatic repayments taken each time you top up²⁴. Suppliers often recommend prepayment meters for customers already in fuel debt, set up to repay a specific amount each week based on affordability³.

Missing key or card, or a supplier going bust

Losing a key or card is an inconvenience, not a crisis. Uswitch's guidance is that you can simply contact your supplier to get a new one sent out, and in the meantime your supplier may be able to authorise a temporary card from your nearest PayPoint, Payzone or Post Office⁷. That temporary card is what stops a lost key turning into a night without power.

For Power NI Keypad customers the position is easier still, because the card is not needed to top up at all⁵. A replacement is posted on request, but allow up to 3 weeks for it to arrive⁵.

If an energy supplier goes out of business, the protections are set out in Ofgem's guidance: "If you have a prepayment meter, you can still top it up as usual"²⁵. Credit is protected and a new supplier is appointed; the new supplier will give information on how to get new key cards and tokens²⁵. Citizens Advice describes the transition period in these terms: during the gap before the new account is live, top up only in small amounts and pay only what is needed to get through²⁶.

If the problem is the meter rather than the key, the supplier's obligations are the same as for any meter fault: they will confirm if there is a problem and should offer a solution, either fixing it remotely or replacing it with a new one²⁴. For help getting to a shop or topping up at all, Citizens Advice notes that your supplier might agree another way to top up, for example by text message, or move you to a smart meter in prepayment mode you can top up online¹³.

When paying in advance is the wrong choice

Prepayment suits some households well. Ofgem says it can help if you are on a tight budget and do not want to pay for what you use all at once, want more control, or are struggling with debt²⁷. But there are situations where it is not safe or practical, and both the rules and the guidance recognise them.

Confused.com lists the grounds on which you can ask to switch away: if it is not safe or practical, for example if you cannot physically access the meter, are disabled or have a health condition, live with young children, are 75 or over, or cannot afford to top up¹⁹. Citizens Advice gives a specific example for England: it might not be safe and practical to be on prepayment if you cannot afford to top up and live with children aged between 2 and 5 years old¹³.

Distance matters too. Ofgem's guidance on involuntary prepayment meters states that "it may not be reasonably practicable to provide a prepayment meter if a consumer needs to travel over two miles to top up their credit and does not have a car"²⁸. A supplier may only install a prepayment meter without your permission under strict conditions, including that other ways of recovering your debt have not worked²⁷.

The obligations on suppliers are firm. Ofgem's position is: "Talk to your supplier if you cannot afford to top up your meter. They must offer to help you, for example by giving you extra credit" in a vulnerable situation²⁷. Scope's guidance sets out when to contact a supplier urgently: if the household needs a continuous supply for health reasons, includes someone over 75 without support, children under 2, no-one able to top up due to incapacity, or residents with severe health issues²². Age UK adds that your supplier should offer emergency credit wherever possible²⁰.

For a household weighing prepayment against other arrangements, the independence question cuts both ways. Prepayment removes dependence on a monthly bill and the risk of a large unexpected debit, and smart prepay removes the dependence on a physical key or card entirely⁴. What remains is dependence on keeping credit loaded, on a working meter, on a top-up outlet or network being reachable, and on the supplier honouring emergency and friendly credit. For more on managing the wider picture, see our guides on how to switch energy supplier, taking a meter reading, and grants that help with energy debt, or start from the home energy how-to guide.