Compare business electricity and gas prices across 30+ UK suppliers and switch without disruption.

Unlike domestic energy, business energy contracts do not automatically revert to a standard variable tariff when they expire. Instead, most suppliers will do one of two things:

Rollover the contract – extend your existing terms for another fixed period (typically 12 months) at whatever rate the supplier chooses, without competitive tendering.

Move you to out-of-contract (deemed) rates – unregulated rates that can be 30-50% higher than contracted rates.

Both outcomes are legal. Both can be avoided with the right preparation. The critical variable is your termination notice window – the period before your contract end date during which you must notify your supplier if you intend to switch.

Termination notice periods vary by supplier and contract type, but the most common windows are:

28 days – most common for micro-businesses (annual consumption below 100,000 kWh electricity or 293,000 kWh gas)

30-60 days – typical for small and medium commercial contracts

90 days – common for larger contracts and multi-site agreements

6 months – some industrial and bespoke contracts, particularly flexible or basket products

Micro-business rules: Since January 2010, Ofgem has required suppliers to send renewal notices to micro-businesses between 60 and 150 days before contract end, clearly stating the new terms and termination notice requirements. If your supplier failed to send this notice, you may have the right to exit without penalty.

If you are unsure whether you qualify as a micro-business, the definition is: fewer than 10 employees (or equivalent full-time) and annual energy consumption below the thresholds above, OR an annual energy spend below £10,000.

Out-of-contract rates (also called deemed rates or rollover rates) are the unit rates suppliers charge when a business has no active fixed-price contract. These rates:

Are unregulated by Ofgem (unlike domestic tariffs)

Are typically 30-50% higher than negotiated contracted rates

Can be applied from the day your contract expires, with no notice

Vary significantly between suppliers – some are far more aggressive than others

For a business spending £30,000 per year on energy under a contracted rate, rolling onto out-of-contract rates could add £9,000 – £15,000 to the annual bill.

The longer you remain on these rates, the more you overpay, some businesses run on deemed rates for 12-18 months before realising, by which point the financial damage is significant.

Switching business energy supplier is straightforward when handled correctly. There are three stages:

1. Serve termination notice; Before you can switch, you need to formally terminate your current contract within the required notice window. This is typically done in writing (email or letter) to your current supplier. Keep a record of the date you sent it and any confirmation you receive.

2. Compare quotes; Once termination is served, we approach our panel of 30+ approved suppliers simultaneously and present results in a like-for-like format, same contract length, same billing structure, so you can compare on unit rate and standing charge without confusion. Quotes are typically valid for 24-48 hours, so we coordinate the process efficiently to avoid prices expiring.

3. Sign and switch; Once you select a new supplier, we handle the contract paperwork, industry registration, and meter transfer administration. A standard business energy switch typically completes within 6-8 weeks. During this time your current supplier continues to supply you, there is no interruption to your energy.

You can find a free termination letter template on our contract termination page.

Consumer-facing comparison websites are built for domestic energy.

When businesses use them, several problems arise: quotes are often indicative rather than live, they only work with a small supplier panel (often the ones paying the highest referral fees), and they offer no ongoing account management after the switch.

At Catalyst, we operate differently:

• We work with 30+ approved suppliers, including suppliers not available on public comparison sites

• We disclose our commission fully before you sign anything

• We advise on contract timing, termination, and rollover risk as part of the service

• We manage the switch end-to-end and remain your contact throughout the contract term

• Through our Cost Stacker™ platform, we monitor your consumption and alert you well ahead of your next renewal

We are TPI (Third Party Intermediary) accredited, a Crown Commercial Service supplier, and registered with the Energy Ombudsman. We have supported more than 1,000 commercial clients across the UK.

Further reading: Switch business electricity supplier covers the electricity-specific side of switching: what actually happens to your supply, how long a transfer takes, and the notice deadlines that decide whether you get a choice.