If your electricity supplier collapses or stops supplying you, Ofgem runs a “Supplier of Last Resort” process. Here is what UK households should do, using the 24,000-customer Tomato Energy case as an example.
Key points
- When a UK energy supplier fails, Ofgem does not let the lights go out: supply continues, and Ofgem runs a bidding process to appoint a new “Supplier of Last Resort” (SoLR), usually within about 14 days.
- In November 2025, supplier Tomato Energy collapsed; Ofgem appointed British Gas as SoLR for its roughly 24,000 customers, with credit balances protected.
- Customers should take and keep a meter reading as soon as they hear their supplier has failed, and should not switch or cancel their Direct Debit themselves – Ofgem and the new supplier handle the move.
A UK household whose electricity supplier goes out of business does not lose power. Ofgem, the energy regulator for Great Britain, runs a standard process – the Supplier of Last Resort (SoLR) mechanism – that moves customers automatically to a new supplier, usually within about two weeks. Customers should still take a few concrete steps to protect themselves.
According to Ofgem’s official guidance for households, a domestic customer’s supply is never cut off just because their supplier has failed. Ofgem selects a new supplier through a competitive process, and that company must show it can take on the extra customers without disrupting its existing ones. If no supplier can be found, Ofgem can apply to the courts for a Special Administration Regime as a backstop – a step reserved for the most serious cases.
The Tomato Energy case
The SoLR process is not theoretical. In November 2025, Basingstoke-based supplier Tomato Energy Limited collapsed into administration; Ofgem’s licence revocation and SoLR direction took effect on 9 November 2025, affecting around 24,000 customers. On 10 November 2025, Ofgem announced that British Gas Trading Limited had been chosen as the new supplier from five competing bids, offering what Ofgem judged the best overall deal, including a deemed tariff below the default price cap (Ofgem newsroom; British Gas press release). British Gas said it would honour outstanding credit balances, including for former Tomato Energy customers who had already left the company but were still owed money.
What customers should do and keep
Ofgem’s guidance is specific: take a meter reading as soon as possible after hearing that a supplier has failed, and keep a written or photographed record of it, so the new supplier can bill correctly from the point of transfer. Customers should not try to switch supplier themselves during this period and should not cancel their Direct Debit – Ofgem and the appointed SoLR manage the move without action being required from the household. Keep the final statement or any email from the old supplier, and watch for a letter or email from the new supplier confirming the deemed contract and tariff.
Smart meters can temporarily lose their “smart” connection during a transfer and stop sending automatic readings; in that case, a manual reading matters even more. Ofgem’s page also lists free advice lines for households that are unsure what to do: Citizens Advice (0808 223 1133) and, in Scotland, Energy Advice Scotland (0808 196 8660).
How supply continues under a Supplier of Last Resort
Under the SoLR guidance, Ofgem invites energy companies to bid for a failed supplier’s customer book; the winning bidder must demonstrate it has the financial and operational capacity to serve the new customers without harming service for its existing ones. Once appointed, customers are placed on a “deemed contract” with the new supplier, usually covered by the energy price cap for roughly six months, after which it reverts to a standard tariff unless the customer actively switches. This is explained further in Ofgem’s blog “How you’re protected when energy firms collapse”.
Credit balances, debt and complaints
For domestic customers, credit balances held with the failed supplier are protected under Ofgem’s rules; the new supplier is given the details and will contact affected households about a refund or credit transfer. Business customers do not have the same automatic protection. If a customer owed money to the old supplier, the new supplier will usually take over that debt and can offer a payment plan; if the debt is not taken over, it may still be owed to the failed supplier or its administrator. Unlike the German Bundesnetzagentur procedure described in the original German-language version of this story, Ofgem’s SoLR process does not involve a separate consumer-group collective claim; disputes instead go through the supplier’s complaints process and, if unresolved, to the Energy Ombudsman.
Frequently asked questions
Will my power be cut off if my supplier goes bust?
No. Ofgem states explicitly that a domestic customer’s energy supply is not cut off when a supplier fails. Supply continues while Ofgem appoints a new supplier.
What is the first thing I should do?
Take a meter reading as soon as you hear your supplier has failed, and keep a written or photographed record of it. Do not switch supplier yourself or cancel your Direct Debit during the transfer.
How long does it take to get a new supplier?
Ofgem says selecting a new supplier through the SoLR bidding process can take up to around 14 days, after which affected customers are placed on a deemed contract with the new company.
Is my credit balance safe?
For domestic customers, yes – credit balances are protected under Ofgem’s rules and should be passed on or refunded by the new supplier. Business customers are not covered in the same way.
Your view
What information would have helped you most if your energy supplier had suddenly stopped trading? Share your view in the comments.
Sources and status
- Ofgem: “What happens if your energy supplier goes bust”, official consumer guidance.
- Ofgem: Supplier of Last Resort, revised guidance.
- Ofgem blog: “How you’re protected when energy firms collapse”.
- Ofgem decision letter: Tomato Energy Limited, SoLR direction effective 9 November 2025.
- Ofgem newsroom: “Ofgem protects customers of Tomato Energy”, 10 November 2025.
- Centrica/British Gas press release, 10 November 2025.
Research and data as of 1 November 2026.
Transparency note: AI-assisted tools were used in researching, structuring and writing this article. The sources used are listed in the article. Publication takes place only after manual editorial approval. Country edition based on an article from NETZ-TRENDS.de, researched for the UK.
