British Gas has taken over the supply of electricity and gas for approximately 23,000 former Tomato Energy customers after the small supplier ceased trading in November 2025. Ofgem, the energy regulator, appointed British Gas as the Supplier of Last Resort following months of regulatory pressure and financial compliance failures at Tomato Energy.
The transfer, which took effect on 10 and 11 November 2025, affects around 15,000 households and 8,000 business accounts. Customers do not need to take any immediate action – their energy supply continues without interruption, and British Gas is contacting them to set up new accounts.
This development marks the latest in a series of UK energy supplier collapses, raising questions about market resilience and regulatory oversight. Here is what is known and what remains uncertain about the British Gas takeover of Tomato Energy.
What happened with the British Gas takeover of Tomato Energy?
Key insights about the transfer
- Tomato Energy was the latest in a series of small supplier failures in the UK energy market, raising concerns about market stability and regulatory oversight.
- British Gas, as the Supplier of Last Resort, guarantees continuity of supply and protects customer credit balances, but customers may see tariff changes after any fixed-rate period ends.
- Ofgem has put Tomato Energy under investigation, likely focusing on compliance with financial and operational regulations.
- Customers are advised not to switch suppliers immediately to avoid complications; British Gas will honor existing terms for a period.
| Fact | Detail |
|---|---|
| Transfer date | 10–11 November 2025 |
| Number of customers | 23,000 total (15k domestic, 8k business) |
| Appointed supplier | British Gas (by Ofgem) |
| Price protection | Existing terms continue; any fixed-rate unchanged until end of contract |
| Customer action needed | No action required; supply continues automatically |
| Investigation status | Tomato Energy under investigation by Ofgem |
| Contact number | British Gas customer service: 0330 100 0056 |
Why did Tomato Energy collapse?
Tomato Energy was a small independent supplier based in Basingstoke that promoted transparent pricing and offered solar export tariffs to customers who generated their own energy. The company faced regulatory scrutiny throughout 2025 after failing to meet financial compliance requirements.
Ofgem initially issued a Provisional Order in May 2025 when Tomato Energy missed its first compliance deadline on 8 May 2025, which was confirmed in July. The company subsequently failed to meet a second deadline on 31 August 2025 regarding liquidity requirements, prompting Ofgem to issue a notice of failure to comply in September.
On 14 October 2025, Ofgem published a Notice of Proposal to Impose a Financial Penalty of £1.5 million following Tomato’s failure to address capital and liquidity deficiencies. The company officially ceased trading on 5 November 2025.
Is Tomato Energy under investigation?
Yes, Tomato Energy is under investigation by Ofgem. The investigation likely focuses on compliance with financial and operational regulations, including the company’s failure to meet liquidity requirements. The exact scope and timeline of the investigation have not been made public.
Since 2021, over 30 UK energy suppliers have collapsed, largely due to wholesale price volatility and regulatory requirements. Tomato Energy’s failure fits this pattern. Ofgem has tightened financial resilience rules, but investigations into failed suppliers help identify systemic issues. The Tomato Energy investigation may lead to further reforms.
How will Tomato Energy customers be affected?
Will my energy prices change after the transfer to British Gas?
Domestic customers are protected by the energy price cap with their new supplier. Existing fixed-rate tariffs from Tomato Energy will be honored until their end date. For customers on standard variable tariffs, British Gas has committed to protection for a limited period, though the exact timeline is not yet clear.
What about Tomato Energy business customers?
Business customers must review their new supply arrangements with British Gas carefully, as different protections apply to non-domestic accounts. British Gas has a dedicated page for business customers with steps to take. Business customers should ensure their direct debit and contact details are updated.
Do I need to do anything as a customer?
No immediate action is required. Supply continues automatically. British Gas will contact customers to set up new accounts. Customers are advised not to switch suppliers immediately to avoid complications; they can switch later without penalty once the transfer is fully processed.
Domestic customers receive: credit balance protection (existing credit balances are protected), price cap protection, no exit fees when switching later, and uninterrupted service during the transfer. Business customers should note that different rules apply.
How can Tomato Energy customers contact British Gas?
Former Tomato Energy customers can contact British Gas on the dedicated number 0330 100 0056. This number is free to call from mobiles and landlines within inclusive minutes. The general British Gas customer service number is 0333 202 9802.
Customers can also manage their accounts online through the British Gas website or mobile app after the transfer is complete. British Gas has been contacting affected customers by email or post with further instructions.
What is the timeline of the Tomato Energy collapse and takeover?
- Prior to November 2025: Tomato Energy faces financial difficulties; Ofgem monitors the situation.
- 8 May 2025: Tomato Energy misses its first compliance deadline; Ofgem issues a Provisional Order.
- July 2025: The Provisional Order is confirmed.
- 31 August 2025: Tomato Energy misses a second liquidity deadline.
- September 2025: Ofgem issues a notice of failure to comply.
- 14 October 2025: Ofgem proposes a £1.5 million financial penalty for capital and liquidity deficiencies.
- 5 November 2025: Tomato Energy ceases trading.
- 9 November 2025: British Gas begins supplying former Tomato Energy customers under the SoLR process.
- 10–11 November 2025: Transfer takes effect; British Gas announces the takeover.
- Ongoing: Ofgem investigation into Tomato Energy continues.
What’s certain and what’s still unclear about the Tomato Energy situation?
| Established information | Information that remains unclear |
|---|---|
| British Gas is now the supplier for all former Tomato Energy customers. | Why exactly Tomato Energy collapsed – details of the financial failure are not yet public. |
| No immediate action is required from customers. | The scope and outcome of the Ofgem investigation. |
| Credit balances are protected. | Whether customers on standard variable tariffs will face price changes soon (though British Gas has committed to protection for a limited period). |
| Existing fixed-rate tariffs will be honored until their end date. | If there will be any compensation for inconvenience. |
Analysis: Tomato Energy and UK Energy Market Context
Since 2021, over 30 UK energy suppliers have collapsed, largely due to wholesale price volatility and regulatory requirements. Tomato Energy’s failure fits this pattern. Ofgem’s Supplier of Last Resort (SoLR) process ensures customers are not left without supply. British Gas, as the largest supplier, frequently takes on these portfolios. The process is designed to be seamless for customers.
Ofgem has tightened financial resilience rules, but investigations into failed suppliers help identify systemic issues. The Tomato Energy investigation may lead to further reforms.
What do official sources say about the British Gas takeover of Tomato Energy?
According to Ofgem’s press release: “Ofgem has appointed British Gas to take on supplying Tomato Energy’s 15,000 domestic customers, and 8,000 non-domestic customers.”
British Gas’s official business page states: “British Gas has acquired the business energy customers of Tomato Energy. Business customers’ supply will be taken over by British Gas.”
What should customers do next?
Former Tomato Energy customers should watch for communications from British Gas via email or post, update direct debit details with British Gas if not already done, monitor their energy account online after the transfer is complete, and avoid switching suppliers until they have clarity on their new tariff terms – switching prematurely may forfeit protection. For more context on the broader implications, read the full analysis on Tomato Energy Collapse and British Gas Takeover. For more information about the energy market, visit our energy market overview and supplier switching guide.
Is British Gas 0333 number free?
Yes, calling a 0333 number from a mobile or landline is included in any inclusive minutes and is generally free or charged at the standard rate.
What is the British Gas customer service number?
For former Tomato Energy customers, the dedicated number is 0330 100 0056. General British Gas customer service: 0333 202 9802.
Will my direct debit change automatically?
If you had a direct debit with Tomato Energy, British Gas will set up a new payment arrangement. You may need to provide new banking details.
Can I switch away from British Gas now?
Ofgem advises against switching immediately. You can switch later without penalty once the transfer is fully processed.
Is Tomato Energy still trading?
No, Tomato Energy has ceased trading. British Gas now supplies all its former customers.
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Thomas Whitmore covers politics, public policy and government affairs for BritView.uk.