Dynamic or fixed electricity price in the UK: your rights

The short answer

A fixed price stays the same for an agreed period. A dynamic price follows the wholesale market hour by hour, so it can be cheaper when you shift your use, and more expensive at peak times.

📜 The rules in the UK

Fixed and dynamic contracts

In Great Britain a fixed tariff keeps your unit rate and standing charge the same until the contract ends; a standard variable tariff moves with the Ofgem price cap. Time-of-use tariffs charge different rates at different times; dynamic versions follow the wholesale market. You usually need a smart meter.

On a fixed tariff you can switch without an exit fee once 49 days or less are left. When it ends you are usually moved to your supplier's standard variable tariff. (citizensadvice.org.uk)
Dynamic time-of-use tariffs can even have negative prices, when you are paid for using electricity at certain times. (citizensadvice.org.uk)

Official source: citizensadvice.org.uk · Checked 2026-09-30

🪜 Step by step

Look at how you use energyA dynamic price suits people who can move use to cheap hours, for example with an electric car, a heat pump or a timer. It needs a smart meter.
Check what is on offerSee below what the rules in the UK say about fixed-price and dynamic contracts and who has to offer them.
Read the risks and the termsBefore you sign, the supplier must explain the costs and risks of a dynamic contract. Check the notice period and any exit fee.
Review after a few monthsCompare your bills with what a fixed price would have cost. You can switch again under your contract terms.

📇 Who to contact

Consumer Council energy price comparison tool (Northern Ireland only; Great Britain has no official comparator) officialCompare electricity and gas offersBefore you switch, or when your price goes up🔗 www.consumercouncil.org.uk/consumers/help-consumers/electricity-oil-and-gas/electricity-price-comparison-tool

Ofgem (Office of Gas and Electricity Markets)Supervises energy companies and explains your rightsFor information, and to report a company that breaks the rules🔗 www.ofgem.gov.uk

Utility Regulator (Northern Ireland)Supervises energy companies and explains your rightsFor information, and to report a company that breaks the rules🔗 www.uregni.gov.uk

❓ Questions

Is a dynamic contract cheaper?

Only if you use a lot of power when prices are low. At peak times it can cost much more than a fixed price.

Do I need a smart meter?

Yes. Hourly prices need a meter that records your use per hour or per quarter hour.

Can a fixed price still go up?

Normally not during the fixed period, but taxes and network charges can change. The rules for the UK are on this page.

📎 Sources

Checked: 2026-09-30

🧭 Is this still correct?

We check this information carefully, but phone numbers, websites and rules change — and sometimes we get something wrong. Spotted a mistake or a change? Let us know below.

🔗 Also useful

More help in the UK

All other problems: who handles whatWho do I contact?100+ things that go wrong — money, housing, work, safety, health, papers, government — and the one desk in the UK that actually handles each: phone, site, and what to say when they pick up.Before it goes wrongCan I?What is allowed, what is not, which permit you need — with the official source.Recognise it firstIs dit veilig?Check a phone number, website or message against 47,000 scam dossiers.

⏱️ Fixed price or dynamic (hourly) electricity contract in the UK: which is right for me?