Whether you are moving into a new office, opening a new branch or taking on a leased shop, the energy supply must transfer to your business name on the day you take occupation. Get the Change of Tenancy (COT) wrong and you can be billed for the previous tenant’s usage, locked into deemed rates for months, or face supply disconnection. This guide walks through the COT process step by step.
What is a Change of Tenancy?
A Change of Tenancy is the formal handover of an energy supply from one occupant to another. Three things happen:
- The outgoing tenant’s account is closed with a final bill.
- The incoming tenant’s account is opened on a deemed contract.
- Meter readings on the date of transfer split the bills cleanly.
Step-by-step: how to handle a COT
1. On the day of move-in
- Take electricity and gas meter readings.
- Photograph the meters with a date-stamped phone camera.
- Note the MPAN (electricity) and MPRN (gas) numbers from the meter or panel.
2. Within 7 days
- Identify the current supplier — ask the landlord or estate agent, or call the local DNO (Distribution Network Operator) for electricity, or the Meter Number Helpline (0870 608 1524) for gas.
- Notify the supplier of the COT, providing your business name, address, opening meter reading and the date of move-in.
- The supplier opens an account in your name on a deemed contract.
3. Within 28 days
- Get quotes from 5-10 alternative suppliers (or via a broker).
- Sign a competitive contract and switch — takes 4-6 weeks to complete.
- Pay the deemed-rate bills in the interim — you cannot avoid them.
Why deemed contracts are 50-80% more expensive
Deemed rates are designed to penalise inertia and protect the supplier from credit risk on a customer who may or may not stay. Typical deemed rates in 2026 are 35-50p/kWh for electricity vs 22-30p/kWh on a competitive 12-month contract.
What happens if you do not do a COT?
- You can be billed for the previous tenant’s usage.
- The supplier may pursue you for the previous tenant’s unpaid debt (rare, but happens).
- You may have your supply disconnected if the previous account is in heavy arrears.
- You will be unable to switch supplier until the supply is correctly registered to your business.
Special cases
Empty property
If the property has been empty for over 28 days, the supply may have been disconnected at the meter. You may need a re-energisation visit (typically £100-300).
HH-metered sites
HH meters require additional Meter Operator and Data Aggregator contracts. Larger sites should use a broker for the COT to ensure all five contracts are in place from day one.
Multi-meter sites
Office blocks and serviced offices may have a single supplier-billed meter that the landlord recharges; some have separate meters per unit. Confirm in the lease which applies.
Frequently Asked Questions
Within 7 days is best practice. Suppliers will accept later notification but you remain liable for energy used from the move-in date so prompt notification protects you from being billed for the previous tenant’s usage.
Typically 50-80% more expensive than a competitive 12-month contract. For a 250,000 kWh/year SME that can be £15-25k/year extra cost — making a quick switch after the COT essential.
The previous tenant remains liable for usage up to the COT date. You are liable from the date you take occupation. A clean opening meter reading is the legal evidence that splits the two bills cleanly.
No — you must first complete the Change of Tenancy with the existing supplier (typically 7-28 days), then sign a new contract and switch (4-6 weeks). You will be on a deemed rate for roughly 4-8 weeks until the new contract goes live.
For electricity: contact your local DNO (use the Energy Networks Association postcode tool). For gas: call the Meter Number Helpline on 0870 608 1524. Both will tell you the current registered supplier so you can complete the COT.
Just moved into a new commercial premises? Get a free 60-second business energy quote — we can run the COT process and switch you off the deemed contract in one go.
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