Can I switch supplier with a prepayment meter and debt?

The debt does not disappear when the supplier changes. It follows the account, and the household stays on a prepayment meter with the new supplier until the arrears are cleared⁵. That is the trade-off at the centre of this page: switching is a route to a cheaper tariff or better service, not a route out of debt.

The £500 rule: switching with prepayment debt under the threshold

The threshold is the single most useful number here. Independent guidance is consistent that a prepayment customer can switch as long as the debt to the current provider is less than £500¹, and that the same £500 applies for each meter, with the debt repaid to the new supplier rather than written off². One comparison site puts it plainly: a prepayment customer can switch as long as they owe less than £500¹¹. Another states that a switch is only possible if the debt to the current provider is under £500, and that the debt transfers with the household¹².

The regulator's own consumer guidance uses the same figure from the other direction: a household can switch where it has a prepayment meter and owes the supplier up to £500³. Debt charities and consumer bodies repeat it, with one adding that arrears above £500 on a prepayment meter are what block the move⁵.

What this means in practice is that a household carrying a modest arrears balance has real choice. It can compare tariffs, switch, and keep repaying at the same rate through the new supplier's top-up mechanism. The debt is not a barrier at that level; it is a condition of the switch. Above £500 on either fuel, the household's options narrow to reducing the balance first, and the routes for that sit with the supplier and the support schemes rather than the switching market.

When you cannot switch: debt over £500 per meter

Above the threshold the switch is refused. Independent guidance is explicit that a prepayment customer cannot switch if they owe more than £500 in gas or electricity⁴, and that owing more than £500 for gas and £500 for electricity prevents a switch¹³. The Welsh-language version of the same advice says a prepayment meter does not prevent switching unless more than £500 is owed to the current supplier for gas or £500 for electricity¹⁴. A debt advice service states the block at more than £500¹⁵.

The comparison with credit meters is worth setting out, because the two regimes work differently. For a household on a credit meter, the trigger is time rather than amount: owing money to the supplier for more than 28 days means the household cannot switch until what is owed is repaid¹⁶. On prepayment, the trigger is the size of the balance. A prepayment household can therefore be in arrears for far longer than 28 days and still switch, provided the total stays under £500 per fuel.

There is a second, separate restriction that catches some households. If any bill is over 28 days old, or a high balance is outstanding on a prepayment meter, the existing supplier may prevent the switch until the outstanding amount is paid¹⁷. That sits alongside the £500 rule rather than replacing it, and it means an old unpaid bill can block a move even where the meter balance itself looks manageable.

Tenants with prepayment meters: your right to switch

Renting does not remove the right to switch. Independent guidance is clear that a prepayment meter and a tenancy together still allow a switch², and that being on a prepayment meter does not prevent a customer switching tariff or supplier, with tenants who are responsible for paying the bills holding the right to switch provider¹⁸. The same right applies where the tenant pays the supplier directly for gas or electricity, including with a prepayment meter¹⁹.

The distinction that matters is between switching supplier and changing the meter. A tenant has the right to change a meter from prepayment to credit, or the reverse, but may be obliged to change it back at the end of the tenancy²⁰. Where the meter itself is to be altered, the landlord's permission is needed²¹. Switching supplier alone does not touch the meter, so it does not raise the same question.

For a tenant in arrears, the practical position is the same as for an owner occupier: under £500 per fuel, the switch can proceed and the debt transfers; over it, the switch is blocked. The prepayment meter stays in place with the new supplier until the arrears are paid off⁵. A template letter exists for tenants and others who want to put a switching request in writing to a supplier while on a prepayment meter²².

Moving from prepayment to a credit meter

The route off prepayment runs through the debt. Once the debt on the account is settled, the supplier may be able to change the prepayment meter to a credit meter⁷. Cost is not usually the obstacle: none of the bigger suppliers charge to change prepayment meters over to credit meters⁸. The supplier may require proof of address, a credit check, or both²³.

There is a separate obligation that does not depend on the debt being cleared. If it is not safe and practical for a household to be on prepayment, the supplier should move it to paying by credit, meaning payment for energy after use rather than before²⁴. That is a safety and practicality test, not an affordability one, and it sits alongside the debt-cleared route rather than behind it.

One caution applies to non-smart credit meters. A supplier might charge if a household switches to a new supplier within 12 months of the meter being fitted, even where it was fitted for free¹². That is a meter-specific charge, distinct from the debt rules, and it is worth knowing before arranging a change and then moving supplier soon afterwards.

Debt built up on a credit meter can also be moved onto a prepayment meter by the energy company, with automatic repayments taken each time the household tops up²⁵. That is how many prepayment arrears balances arise in the first place, and it explains why the repayment element is built into the top-up rather than billed separately.

Smart meters: switching between prepay and credit mode without a new meter

A smart meter changes the mechanics of all of this. Suppliers can switch consumers from credit to prepayment mode without the cost of a new meter being added to existing debt⁹. The same source confirms that a household with a smart meter can switch from prepayment to credit without a new meter being installed⁹. Smart Energy GB states that a supplier can change between credit and prepay without a whole new meter¹⁰, and that smart prepay customers can switch between payment modes without physically changing the meter²⁷.

In prepayment mode, a smart meter can add credit automatically or without a visit to a shop²⁸. Switching from an existing gas or electricity prepay meter to a smart credit meter is described as straightforward for customers who meet the conditions³⁰.

The consent question follows from the same technology. A supplier can install a prepayment meter without permission where a household is building up energy debt and other ways of recovering it have not worked³¹. It can also get a warrant to enter the property and install a prepayment meter, or remotely switch an existing smart meter to prepayment mode³¹. For tenants, a supplier might install a smart meter in prepayment mode, or switch an existing smart meter to prepayment mode¹⁹. Where a supplier switches an existing supply meter to prepayment mode without consent, official guidance for heat networks requires it to ensure the consumer receives prepayment meter credit, unless that is technically infeasible or outside the supplier's control³⁵.

Compensation may be available for households moved onto prepayment in the past. Independent guidance flags customers moved onto a prepayment meter between 1 January 2022 and 31 January 2023 as potentially owed compensation where a meter was installed or they were switched over remotely²¹. Official guidance frames the window as being forced onto prepayment between 1 January 2022 and 21 January 2023 where the supplier did not follow the rules properly³¹.

What happens once the debt is paid off

While arrears remain, each top-up does two jobs. As well as paying the unit rate for the energy used, a little extra goes towards what is owed²¹. Suppliers often recommend prepayment meters for customers already in fuel debt, set up to repay a specific amount each week based on affordability¹⁸. That is why the balance falls steadily rather than in one payment.

Once the debt is cleared, the repayment element stops and the top-up buys energy alone. At that point the supplier may be able to move the household to a credit meter⁷, and none of the bigger suppliers charge for the change⁸. Until then, the household remains on prepayment with whichever supplier holds the account, and the debt stays with it⁵.

For energy independence, the picture is mixed. A prepayment household under the £500 threshold can shop across the market, which is real leverage over price and service, and a smart meter removes the need for a new meter when moving between prepay and credit⁹. What remains is dependence on the supplier holding the debt, on the top-up mechanism, and on the meter mode the supplier controls. Clearing the balance is what converts that into a free choice of payment method. Households weighing the wider steps can start from the full UK guide to home energy, and the mechanics of topping up and emergency credit are set out in how to top up a prepayment meter.