Co-operative Energy has blamed ongoing problems with its new IT system as the reason why it was the most complained about energy provider in the third quarter of the year.

The Ombudsman Services says it received 136 complaints per 100,000 customers about Co-operative Energy in the three months to September, 50% higher than any other supplier. See's How to Complain guide if you're unhappy with your firm's service.

Co-operative Energy has been plagued with problems after it upgraded its computer systems in March, with many customers complaining of being locked out of their online accounts or not receiving their bills following the switch (see the Co-op Energy faces customer backlash MSE News story for more on this).

Responding to the findings, a Co-operative Energy spokesperson claims it has made "significant progress" on resolving its technical issues, saying: "We would like to thank customers for their patience and continued support in recent months.

"We have made significant progress to resolve a number of technical issues which ultimately related to the introduction of a new IT system. We will continue to make further improvements to ensure our customers receive the high level of service they expect and deserve."

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Overall energy complaints

Looking at the broader industry, the energy ombudsman says it received a total of 13,212 complaints in the third quarter, slightly lower than the previous quarter's total of 13,490.

Disputed charges, inaccurate invoices and missing bills were by far the most common complaints, accounting for nine out of every 10 (87%) complaints received by Ombudsman Services.

Below is a breakdown of the total number of complaints Ombudsman Services received per 100,000 customers:

  • Co-operative Energy: 135.92
  • Scottish Power: 89.20
  • Npower: 71.39
  • First Utility: 41.32
  • E.on: 14.50
  • Ovo Energy: 10.41
  • British Gas: 8.94
  • EDF: 7.33
  • Utility Warehouse: 5.62
  • SSE: 3.88

Commenting on the findings, chief ombudsman Lewis Shand Smith says: "Consumers are rightly more demanding of their energy suppliers than ever before, taking service as well as cost into account.

"Having easy access to these figures gives consumers the power to make informed decisions about their energy provision."