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Small energy companies

iSupply Energy

By Sarah Ingrams

Article 11 of 20

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iSupply Energy

iSupplyEnergy began to sell energy to domestic customers in August 2012. It claims to be the cheapest supplier in many parts of the UK. 

iSupplyEnergy is based in Bournemouth, Dorset. Its tariffs have a simple structure and prices are made up of a fixed unit rate and a daily standing charge. You can only switch to iSupplyEnergy online.

Previously a British-owned supplier, iSupply was bought by European gas and electricity giant Vattenfall in June 2017.

Initially, iSupply only offered electricity tariffs. It began supplying gas as well from December 2015. iSupply doesn’t offer a green tariff. 

You can find out how iSupplyEnergy's prices compare with your current deal by finding the cheapest gas and electricity with Which? Switch now.

iSupplyEnergy customer satisfaction

iSupplyEnergy comes joint eighth out of 23 energy companies rated by 8,917 members of the public in the annual Which? customer survey – the biggest of its kind.

The table below shows the breakdown of iSupply's score from our latest survey.

iSupplyEnergy survey results
Area of performance Star rating
Customer service and complaints handling
Value for money
Bills (accuracy and clarity)
Helping you to save energy
Customer score 70%

(Survey: October 2016, responses of 41 iSupplyEnergy customers.) 

Find out how iSupplyEnergy compares with other energy companieswe reveal the full results of the best and worst energy companies.

Which? verdict on iSupplyEnergy

iSupplyEnergy has competitive rates. Customers seemed largely happy with customer service, with one commenting that 'iSupply is easy to contact by email and answers quickly.' Another described its customer service team as 'friendly and polite.' 

Customers seemed largely happy with customer service.

However, iSupply had one of the worst rates for complaints resolution in the first half of 2016. Only 20% of complaints received in the first quarter and 15%  received in the second quarter were resolved on the same or next working day, which is the worst rate of all the energy companies investigated. And only 85% were resolved within eight weeks. The best energy firms resolve close to 100% of their complaints.

Pros: It offers competitive electricity and gas tariffs

Cons: A few customers felt it could be better for helping them save energy

iSupplyEnergy fuel mix

Where iSupplyEnergy gets it fuel:

  • 17% Coal
  • 32% Natural Gas
  • 24% Nuclear 
  • 3% Other
  • 24% Renewables

(Note: This information was correct January 2017.)

Fed up with high bills and slack customer service? Use Which? Switch to find the cheapest gas and electricity.