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Change of Tenancy

What is a Change of Tenancy (COT)?

A Change of Tenancy, almost always called a COT, is the energy industry process of switching who is responsible for a gas or electricity supply when a business moves in or out of a property. It is not a supplier switch; the supply stays with whoever was serving the meter on day one, but the contract behind it is closed out for the old occupier and a new one opened for the new occupier. The mechanics sound simple. In practice, COTs are one of the most common sources of bill problems for UK businesses — late notifications, missed reads, weeks on deemed rates, lingering charges for the previous occupier's usage — and worth knowing how to handle properly.

CoT applies across business energy supplies. Electricity, gas, and business water. Whenever a site changes occupier mid-contract.

The COT process applies whether you are taking over a unit, moving out, or selling a business as a going concern. The supplier needs to know two things: when responsibility transferred, and who is taking it on. Get those two right at the right time and the process is administrative. Miss either and the next bill becomes a problem.

What a COT actually does

A COT triggers three administrative steps at the supplier end:

• The previous occupier's account is closed on the transfer date, with a final bill produced up to that date.
• A new account is opened for the incoming occupier from the same date forward.
• Meter readings are matched up at the changeover so both parties only pay for energy they actually used.

The physical supply does not change. The MPAN (electricity) or MPRN (gas) identifying the meter stays the same. What changes is the contractual relationship — who the supplier is billing and at what rates.

When a COT is needed

A COT applies in any of these situations:

• A new business taking on a commercial unit or premises for the first time.
• An existing business moving out and a new tenant moving in.
• The sale of a business as a going concern where the buyer takes on the premises.
• A change of company name following a restructure or sale.
• A change of legal entity even where the trading name continues.

It does not apply when the same legal entity continues to occupy the premises — even after restructure, renaming or rebranding — as the billing entity is unchanged.

Information the supplier needs

To process a COT cleanly the supplier needs:

• The MPAN or MPRN for the supply (or the supply address if the meter ID is not known).
• The exact change date when responsibility transferred.
• Meter readings on the change date from both parties wherever possible.
• The incoming occupier's details: legal entity name, registered address, billing contact.
• The outgoing occupier's forwarding address for the final bill.

The information should be sent in writing (email or supplier portal) to create a clear audit trail. Phone notifications happen but get lost.

How the COT process works

The standard sequence:

1. The incoming occupier or their broker notifies the existing supplier that they are taking over the supply, providing the information above.
2. The supplier closes the previous account on the change date.
3. The supplier produces a final bill for the outgoing occupier up to that date, calculated using the change-date meter reading.
4. A new account is opened for the incoming occupier from the change date forward.
5. The incoming occupier is normally placed on the supplier's deemed (out-of-contract) rates while they decide whether to stay or switch.
6. The incoming occupier either negotiates a new contract with the existing supplier or switches to another supplier through the normal switching process.

The change date itself is usually the date of completion (for a sale) or the lease start date (for a new tenancy). It is normally backdated only with documentary evidence.

COT and deemed rates

Once the new account is opened, the incoming occupier sits on deemed rates until they either sign a contract with the existing supplier or switch. Deemed rates are typically 30 to 100 per cent higher than equivalent fixed-contract rates, and the gap can be material if the changeover sits unaddressed for months. The figures used below are illustrative and meant to show the shape of the cost difference rather than current market rates — your own contract and deemed rates will be on your bill.

This is the single biggest financial risk in a COT. Even a clean COT done on time leaves the incoming occupier on default pricing until they take action. Negotiating a new contract — or running a market comparison and switching — should be on the to-do list from day one of moving in.

To give a sense of how the cost gap scales over time, here is a simple example. Assume a fixed-contract unit rate of 25 p/kWh and a deemed-rate equivalent of 38 p/kWh — a 13 p/kWh gap between the two.

Example only. Deemed rates vary from supplier to supplier (and over time), so the gap on your own bill will differ — check your contract and your current supplier’s published deemed rates.

Common COT errors

• Late notification. The outgoing occupier continues to receive bills for energy they did not use, weeks or months after moving out.
• No meter reads provided. The supplier estimates the split between old and new occupier and almost always gets it wrong by a meaningful amount.
• Incoming occupier never opens an account. The supplier puts the supply on deemed rates billed to the previous occupier's name (or to “the occupier”) and bills accumulate.
• Multi-meter sites partially transferred. Some meters are transferred, others are missed — old occupier keeps receiving bills for forgotten meters.
• Wrong change date. Either party tries to claim a more convenient date than the actual handover, supplier rejects and the COT stalls.

COT as the incoming occupier

If you are moving into a commercial premises:

1. Identify the meters on day one — MPAN for electricity, MPRN for gas. Either is shown on the meter or available from the supplier or via the Find My MPRN service.
2. Take meter reads the day you take occupation. Photograph the meter face with the date if possible.
3. Contact the existing supplier within seven days of moving in to open a new account, providing reads and your legal entity details.
4. Decide whether to stay on the existing supplier's contracted rate or switch — and do it quickly. Every month on deemed rates is more expensive than it needs to be.
5. Check the de minimis VAT threshold and qualifying use criteria — moving may change your eligibility.

COT as the outgoing occupier

If you are moving out:

1. Notify the supplier of your leaving date as soon as you know it. Forty days notice is the practical minimum to avoid problems.
2. Take a meter read on the day you leave. Photograph it.
3. Provide your forwarding address for the final bill.
4. Confirm the new occupier's details if you have them; if not, ask the supplier to use the address on a no-named basis until the new occupier comes forward.
5. Cancel any direct debit only after the final bill has been issued and settled. Cancelling earlier leaves the supplier no automatic way to collect, which slows down account closure.

For related concepts, see what a final bill is, how deemed rates work, and the Letter of Authority required if a broker is acting on your behalf.

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