Best business energy supplier: how to judge one for your business

Why we do not publish a league table

Biz Energy takes no commission and is not a supplier or broker, so we have no reason to push anyone. We also do not rank suppliers because "best" depends on your usage, your sector, your credit position, your contract timing and what you value. A cheap rate that comes with estimated bills and poor service can cost more than a slightly dearer supplier that reads your meter. Many "best supplier" lists online are written by sites that are paid commission when you buy, so read them with that in mind.

Instead, use the checklist below on every supplier you are offered. You can look up the main names on our list of UK business energy suppliers.

1. Price: judge the whole annual cost

The cheapest supplier is the one with the lowest total yearly cost for your usage, including the standing charge and the contract terms. The unit rate alone misleads. Example, with invented rates for a café using 18,000 kWh:

Supplier	Unit rate	Standing charge	Annual cost
X	26.0p	80p/day	4,680 + 292 = £4,972
Y	27.5p	45p/day	4,950 + 164.25 = £5,114.25
Z	25.0p	200p/day	4,500 + 730 = £5,230

(18,000 × 0.26 = 4,680; 365 × 0.80 = 292; 18,000 × 0.275 = 4,950; 365 × 0.45 = 164.25; 18,000 × 0.25 = 4,500; 365 × 2.00 = 730.) The lowest unit rate, Z, is the most expensive overall. Use the business energy cost calculator, and see is the cheapest deal the best.

For reference, the DESNZ average for non-domestic electricity in April to June 2026 was 24.51p/kWh including CCL. Compare your quote to your own bill.

2. Contract terms

• Fixed or pass-through? See pass-through vs fixed charges.
• Length, exit fees and what happens at renewal. See contract terms to check.
• Automatic rollover. For microbusinesses, rollovers are limited to 12 months and the supplier must first send renewal information, but you still need to diarise your dates.
• Broker fees in the Principal Terms.

3. Billing accuracy and metering

Do they bill on actual readings, with smart or advanced meters where available? Estimated bills lead to nasty catch-ups. Microbusinesses are protected from back-billing beyond 12 months in most cases, but small businesses are not. See back billing and business smart meters.

Service, resilience and fit

4. Service and how you reach them

Ask: Is there a named account contact? Can you reach them by phone and email? How do they handle moves, readings and queries? Test this before you sign by contacting their sales and support lines and seeing how fast they reply.

5. Complaints and disputes

Every supplier should have a complaints process. Microbusinesses and small businesses can take unresolved complaints to the Energy Ombudsman, after 8 weeks or a deadlock letter and within 12 months. Look for a supplier's complaints page and read how it describes this. We do not quote review-site scores because they are unverified and easily gamed. See energy disputes and the Ombudsman.

6. Financial resilience

Suppliers can and do fail. Ofgem says your supply carries on if yours goes bust: it appoints a replacement supplier, usually within a few days and no more than 14. Your old tariff ends and the new supplier puts you on a deemed contract, which can cost more, although you can then choose a tariff or switch without exit fees. Business credit balances are not covered by Ofgem's safety net, so you may have to claim from the administrator. See what happens if your supplier goes bust. Be cautious of rates far below the market.

7. Green claims

If you want renewable power, check how it is backed, for instance by REGO certificates. See green business tariffs and are green tariffs really green.

8. Do they actually serve businesses like yours?

Some suppliers focus on microbusinesses, some on large industrial customers, and some have sold or merged their small-business books. For example, npower's small-business customers moved to E.ON Next, and Drax sold most of Opus Energy's small-business meter points to EDF, completing in September 2024. See npower Business Solutions and Drax and Haven Power.

A scorecard you can use

Score each supplier from 1 to 5 on the eight areas above, weight them by importance to you (a pub may weight metering and billing; a seasonal business may weight flexibility), and add them up. A simple example: price weight 3, terms weight 2, billing weight 2, service weight 1. A supplier scoring 4, 3, 5, 3 gets (4×3)+(3×2)+(5×2)+(3×1) = 12+6+10+3 = 31 out of a maximum of 40.

Tip: Our neutral supplier guides, reached from the UK suppliers list, explain ownership, contact routes and complaints for each name. Read the guide for every supplier on your shortlist before deciding.

Questions to put to every supplier before you sign

Send the same short list by email to each supplier or intermediary, so the answers are in writing and directly comparable:

1. What is the unit rate and standing charge for each meter, and are both fixed for the whole term?
2. Which charges, if any, can be passed through to me during the term?
3. Does the price include the Climate Change Levy, and which VAT rate will you apply?
4. What is the start date, end date and the deadline for giving notice at renewal?
5. What happens if I move premises, close or sell the business during the term?
6. Is there a broker cost in the price, and what is it in pounds over the whole contract?
7. How will my meter be read, and how often should I expect an actual reading?
8. Which complaints process do you use, and can my business use the Energy Ombudsman?

A supplier that answers all eight clearly is already showing you something about its service. Vague answers, or a refusal to put a price in writing, should cost it points on your scorecard.

Weighing a cheaper price against weaker service

Suppose supplier X in the table above (£4,972 a year) has a record of estimated bills, while supplier Y (£5,114.25) offers a smart meter and a named account manager. The gap is £5,114.25 minus £4,972 = £142.25 a year, or about £11.85 a month. If poor billing would cost you even a couple of hours a quarter chasing corrections, Y may be the better choice. Put a value on your time before you let the lowest figure decide for you.

Next steps

• Get quotes in the same format from three suppliers.
• Score them using the list above.
• Check the contract terms, then follow how to switch business energy supplier.