Business energy contract ended? Check what happens next

Start by identifying the arrangement

The Ofgem supply and complaints framework discussed here applies to Great Britain; Northern Ireland has a separate energy regulatory framework.

A deemed contract arises by law when energy is supplied without an agreed supply contract in the relevant circumstances. Moving into premises and using the supply before agreeing terms is a familiar example. An expired contract can also lead to a deemed arrangement where it makes no provision for what follows.

Out-of-contract terms come from the agreement you already made. That contract explains what happens after its fixed period. A rollover clause can instead renew an arrangement automatically. An evergreen contract continues without a fixed end date, subject to its terms and applicable rules.

Do not accept an account label as the whole explanation. Ask the supplier to identify the clause or statutory basis it relies on and the date the present arrangement began. That gives you something specific to compare with your paperwork.

For a business with several meters, repeat the check for each supply. Gas and electricity can have different end dates, and a second unit may have been added under a separate agreement. One renewal letter is not a complete record of the business's energy commitments.

Why a bill can change after the fixed term

A fixed-term price agreement applies for the period and on the conditions you accepted. Once it ends, the next set of terms may produce a different bill. That does not establish that every increase is correct, or that the business is on a deemed contract.

First compare equivalent things. Is the new document a bill for energy used, an estimated bill or a notice changing the Direct Debit? Does it cover the same number of days? Have readings changed from estimated to actual? Those details can explain an apparent jump separately from a contract change.

Ofgem requires suppliers to take all reasonable steps to prevent deemed terms being unduly onerous. Its guidance describes assessment of the supplier's own deemed and contracted business, including reviewing deemed rates. It does not publish a business deemed tariff that every supplier must charge.

On 9 September 2026, Ofgem's consultation on revised deemed-contract guidance was closed and awaiting a decision. Proposed changes are therefore not treated here as rules already in force.

Ask the supplier to explain the dates, readings and charging basis on the disputed bill. A useful answer separates consumption, time-based charges, taxes and any other contract components. A statement that your account is out of contract does not answer a question about an incorrect opening reading or duplicated charge.

Establish how you can leave

A deemed arrangement is not a new fixed-term commitment accepted by the customer. You can seek an agreed contract with the existing supplier or arrange a transfer. However, outstanding debt and the switching rules that apply can still affect the transfer process. Confirm whether the supplier has raised an objection and why.

For an out-of-contract or automatically renewed arrangement, read the relevant conditions rather than assuming the deemed position applies. Ask for the proposed final supply date, any notice requirement and the basis of any termination charge. If the supplier says a renewal took place, request the notice history.

Do not cancel a payment instruction as a substitute for ending a supply contract. It does not establish a final supply date or resolve what is owed. If the account is disputed, state the dispute clearly and ask how the supplier will handle billing and collections while investigating.

Make the sequence visible to anyone organising a new agreement. They need the current supplier, supply identifiers, contract position and relevant correspondence. If one person is negotiating while another is challenging the account, keep their instructions consistent.

The existing guide to when you can switch business energy explains the wider timing questions. Neither a quote nor an enquiry is evidence that the old supplier has accepted a termination or that the new supply has begun.

Check microbusiness rights against current rules

Microbusiness status brings additional protections, but small in everyday language is not enough. Qualification can depend on business size or annual energy consumption, and the consumption route is assessed separately for each fuel. Our guide to micro and small business energy rights sets out the tests.

There is a particular trap in older renewal guidance. Ofgem's 2022 reforms removed the general termination-notice requirement for microbusiness contracts, except for evergreen arrangements. Older factsheets referring generally to a maximum notice period need to be read alongside those changes. Ask the supplier which current rule it applies to your contract.

Preventing an automatic rollover is also a separate issue from switching after a fixed term. If you do not want the contract renewed automatically, put that instruction in writing and get an acknowledgement. Keep the date and the address or account channel used to send it.

Microbusiness rollover periods are capped at 12 months. That is not a statement that every contract a microbusiness actively agrees must last no longer than that. A negotiated fixed-term agreement and an automatic rollover are different arrangements.

Create a record of the end date, renewal communications and any instruction against rollover. If paperwork uses a last termination date, ask what action that date governs. The aim is to avoid missing a required instruction while also challenging reliance on an obsolete notice rule.

Do not rely on a cooling-off period

Business energy contracts generally have no cooling-off period. An agreement made over the telephone can be binding. Being a very small company does not automatically give you the cancellation rights associated with buying a household service.

Before accepting, ask for the supplier, contract duration, commencement arrangements and full principal terms. Confirm which charges are fixed and which can change. Make sure the person agreeing has authority to do so and understands whether the conversation is an enquiry or an acceptance.

If a broker is involved, examine its agreement as well as the energy contract. Ask what authority it needs, what it will do with that authority and how it is paid. A document authorising information gathering should not be treated casually if its wording also permits contractual action.

When the contract has already been agreed and something appears wrong, collect the evidence. Request the recording or written acceptance record and identify precisely what was represented. A complaint about misrepresentation needs facts; a general statement that you changed your mind addresses a different issue.

Our energy broker commission guide explains where to look for the remuneration disclosure. Reading it before signing helps you ask a specific question about the proposed contract without assuming every broker uses the same payment arrangement.

Separate back billing from an unpaid bill

Back billing means being charged for energy used in an earlier period that was not correctly billed at the time. It is different from a bill correctly issued earlier that remains unpaid. The age of the consumption alone does not tell you which situation applies.

Ofgem's back-billing protection generally prevents suppliers recovering previously unbilled charges for energy used more than 12 months earlier from protected domestic and microbusiness customers. Exceptions apply, including obstructive or manifestly unreasonable behaviour. The protection is not a general write-off for overdue invoices and does not extend automatically to every non-domestic customer.

If the supplier issues a large catch-up bill, ask for a period-by-period explanation. Which readings were used? Which amounts were already billed? Why was the earlier billing inaccurate? What is the supplier's assessment of your microbusiness status and any claimed exception?

Keep photographs of readings, submission confirmations and previous bills. If the supplier says it could not get readings, your records may help work out what access or information you provided. Avoid arguing solely from the total, because the answer may differ across the periods within the same document.

A complaint should identify the correction requested: a reading, a date, an account allocation or application of the back-billing rules. That is easier to investigate than a broad demand to remove the entire balance.

What to do next

Bring the account into a state where somebody else can understand it without a long telephone explanation. A recent bill and a short chronology are a useful starting point, particularly if the business has changed premises or legal entity.

1. 1Identify each meter and the business legally responsible for the supply.
2. 2Find the fixed-term end date and ask which terms now apply.
3. 3Submit an actual reading through the supplier's accepted channel and retain the receipt.
4. 4Request the renewal and termination position in writing, including any rollover evidence.
5. 5Separate disputed billing from the information needed for a new agreement.
6. 6Gather annual usage, current terms and relevant correspondence before comparing options.

Give the supplier a clear list of unanswered questions. Keep its responses together and note any promised follow-up date. If the issue remains unresolved, use its complaints process and check the Energy Ombudsman's current eligibility and escalation requirements.

You do not need to reconstruct every historic invoice before exploring a replacement contract. You do need enough evidence to understand what you are leaving and when. That reduces the risk of solving an awkward bill by agreeing another contract you have not properly read.