Electricity and gas supplier

SmartestEnergy: contact, login and rates

Q: What is the SmartestEnergy business phone number?

Existing customers: +44 (0) 1473 234151 (8.30am-5pm, Monday to Friday). General enquiries (central reception): +44 (0) 20 7448 0900. SmartestEnergy Business (small businesses) - customer services, 8.30am - 5pm, Monday to Friday: 01903 703400. SmartestEnergy Business - quotes (Mon-Fri, 8.30am-5pm): 01903 259976. SmartestEnergy Business - meter readings (24/7 freephone): 0800 088 4581. SmartestEnergy Business - broker support (8.30am-5pm, Monday to Friday): 01903 703411. Numbers taken from SmartestEnergy's official contact page, checked 12 September 2026.

Phone numbers, online account login, out-of-contract rates and who owns the company, checked against SmartestEnergy's own website.

Facts checked against official sources on 12 September 2026

Existing customers +44 (0) 1473 234151

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SmartestEnergy is owned by Marubeni Corporation and supplies electricity and gas to UK businesses through two companies: SmartestEnergy Limited for large users and SmartestEnergy Business Limited for smaller ones. It holds about 10% of the UK commercial and industrial power retail market. It also works with renewable generators and offers corporate PPAs.

SmartestEnergy business contact numbers and login

Existing customers +44 (0) 1473 234151 8.30am-5pm, Monday to Friday

General enquiries (central reception) +44 (0) 20 7448 0900

SmartestEnergy Business (small businesses) - customer services, 8.30am - 5pm, Monday to Friday 01903 703400

SmartestEnergy Business - quotes (Mon-Fri, 8.30am-5pm) 01903 259976

SmartestEnergy Business - meter readings (24/7 freephone) 0800 088 4581

SmartestEnergy Business - broker support (8.30am-5pm, Monday to Friday) 01903 703411

Emergencies are not handled by your supplier. If you smell gas, call the National Gas Emergency Service on 0800 111 999. For a power cut, call 105 to reach your local network operator.

We are not SmartestEnergy. Numbers and links are taken from SmartestEnergy's own website and were checked on 12 September 2026.

About SmartestEnergy

Status	Trading
Supplies	Electricity and gas
Business customers	Microbusinesses, Small and medium businesses, Industrial and commercial, Generators
Owned by	Marubeni Corporation
Supplying company	SmartestEnergy Limited
Company number	03994598 on Companies House
Head office	The Columbus Building, 7 Westferry Circus, London E14 4HD
Founded	2000
Formerly	Dual Energy (renamed 2020)
Energy Ombudsman	Yes, refers eligible complaints
On our comparison panel	Yes
Website	smartestenergy.com

SmartestEnergy Limited supplies large businesses using more than 300,000 kWh a year or spending more than £50k. Smaller businesses are supplied by SmartestEnergy Business Limited (formerly Dual Energy), based in Worthing.

SmartestEnergy business energy products

These are the business products SmartestEnergy describes on its own website. Availability depends on your business size, meter and region.

Fixed energy contracts
Flexible energy contracts
Standard Renewable
Natural Renewable
Traceable Renewable Supply
Specific Renewable
Corporate PPA
SmartFix (SME)
SmartFlex (SME)
SmartFix Zero Standing Charge (SME)
Low User (SME)
SmartPay (SME)

SmartestEnergy deemed and out-of-contract rates

If your fixed contract ends without a new one in place, or you move into premises supplied by SmartestEnergy without agreeing a contract, you'll pay its deemed or out-of-contract rates. These are typically well above fixed contract prices.

SmartestEnergy publishes its out-of-contract and deemed rates as PDFs on its support pages.

See SmartestEnergy's current published rates

For context: in Q2 2026, UK businesses using up to 20,000 kWh of electricity a year paid an average of 38.36p per kWh all-in, which spreads the standing charge across every unit and includes the Climate Change Levy. A bill shows a unit rate plus a daily standing charge, so use our cost calculator to turn your rates into an all-in figure before comparing. Prices for every business size.

SmartestEnergy: key facts and recent news

Nov 2021Ofgem appointed SmartestEnergy Business Limited as electricity Supplier of Last Resort for MA Energy Limited's customers. Ofgem
2024Its small business arm, SmartestEnergy Business (formerly Dual Energy, bought by SmartestEnergy in 2019), reports over 50,000 business customers and 84,000 active supply points. smartestenergybusiness.com · About us
Apr 2026SmartestEnergy holds about 10% of the UK commercial and industrial power retail market and about 9% of renewable energy procurement. marubeni.com
Apr 2026SmartestEnergy bought an 85% stake in Spanish supplier Factor Energia for €204 million, entering Iberia and Latin America. marubeni.com
Jul 2026SmartestEnergy signed a 15-year CfD power purchase agreement with greentech for the 26MW Chalkpit Solar Farm in Guston, Kent. smartestenergy.com · Smartestenergy partners with greentech for first uk solar project

SmartestEnergy and energy brokers

SmartestEnergy Limited's code of conduct requires brokers to make customers aware of the commission they receive and to join the microbusiness dispute resolution scheme. Its small business arm, SmartestEnergy Business, works with more than 140 broker partners.

Switching from SmartestEnergy

You can usually switch away from SmartestEnergy when your fixed contract ends, and at any time if you're on deemed or out-of-contract rates. Check your contract for any notice you need to give so you don't roll onto renewal prices.

Find your contract end date on a recent SmartestEnergy bill or in your online account.
Check whether you need to give written notice, and by when.
Compare electricity and gas prices for your premises, including from SmartestEnergy.
Agree a new contract. Your new supplier handles the switch, and your supply isn't interrupted.

Compare prices for your business

SmartestEnergy FAQs

What is the SmartestEnergy business phone number?

Existing customers: +44 (0) 1473 234151 (8.30am-5pm, Monday to Friday). General enquiries (central reception): +44 (0) 20 7448 0900. SmartestEnergy Business (small businesses) - customer services, 8.30am - 5pm, Monday to Friday: 01903 703400. SmartestEnergy Business - quotes (Mon-Fri, 8.30am-5pm): 01903 259976. SmartestEnergy Business - meter readings (24/7 freephone): 0800 088 4581. SmartestEnergy Business - broker support (8.30am-5pm, Monday to Friday): 01903 703411. Numbers taken from SmartestEnergy's official contact page, checked 12 September 2026.

How do I log in to my SmartestEnergy business account?

You can log in to your SmartestEnergy business account on the supplier's website. If you haven't registered yet, you'll usually need your account number from a bill.

Who owns SmartestEnergy?

Marubeni Corporation. Contracts are with SmartestEnergy Limited (company number 03994598).

What are SmartestEnergy's out-of-contract rates?

SmartestEnergy publishes its deemed and out-of-contract rates on its website. These rates are usually much higher than fixed contract prices, so compare before your contract ends. See SmartestEnergy's published rates.

Can I complain about SmartestEnergy to the Energy Ombudsman?

Yes. SmartestEnergy's complaints information refers eligible business customers to the Energy Ombudsman. You normally need to complain to the supplier first and wait eight weeks, or receive a deadlock letter, before the Ombudsman can look at it.

Can I switch away from SmartestEnergy?

Yes, usually at the end of your contract, or at any time if you're out of contract or on deemed rates. Check your contract for notice requirements so you don't roll onto renewal rates.

Sources

Facts on this page come from SmartestEnergy's official website, Companies House, Ofgem and the parent company's published reports and announcements, checked on 12 September 2026.

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