Co-op Energy was a customer service darling last December, with 63% of its customers rating it great and just 7% rating it poor. But in a staggering turnaround, just six months later over half of its customers (56%) rate its service as poor and just 22% rate it great. 

It's the biggest energy firm fall from grace – with Co-op Energy dropping from fifth best for customer service in December to thirteenth place now – we've seen since beginning our biannual energy customer services poll.

It's likely Co-op Energy's downfall is related to an upgrade to its online customer service and billing system in March, which left some unable to log in to their account and others experiencing delays switching (see the Co-op Energy faces customer backlash following bungled system upgrade MSE News story).

At the time, we saw tweets from frustrated customers such as @blondiesj: "New website not working. Can't input meter readings. Incorrect balance. Called last week but still wrong." And @zubairg: "Online system doesn't work, errors keep coming up. Didn't get opening meter readings. Took supply over without contacting me."

But we're still hearing reports from Co-op Energy customers saying its online system isn't working and that they're having difficulties getting through to customer services because of heavy demand. Join our free Cheap Energy Club to see if you can switch and save.

Our poll also saw Good Energy top the table again with 88% of people who voted for it rating it great, while at the other end of the scale is Extra Energy, with only 18% of its customers voting its service as great, compared with 41% in December 2014.

The results

Here is the full table from our latest energy company service poll:

Energy company service rating, May 2015(Results and ranking from December 2014 in brackets)

Rank Provider Great OK Poor
1 (1) Good Energy 88% (91%) 8% (4%) 4% (5%)
2 (2) Ebico 79% (82%) 19% (12%) 2% (5%)
3 (3) Ovo Energy 82% (81%) 12% (12%) 6% (7%)
4 (n/a) Ecotricity 79% (82%) 8% (3%) 13% (15%)
5 (4) Flow Energy 68% (76%) 21% (18%) 11% (5%)
6 (6) EDF 57% (55%) 31% (33%) 12% (12%)
7 (7) E.on 54% (53%) 36% (33%) 10% (14%)
8 (8) SSE 53% (49%) 31% (34%) 16% (17%)
9 (10) First Utility 48% (43%) 27% (24%) 25% (33%)
10 (9) British Gas 41% (37%) 37% (40%) 23% (23%)
11 (n/a) Sainsbury's Energy 37% (43%) 34% (34%) 28% (22%)
12 (12) Npower 21% (17%) 26% (22%) 53% (61%)
13 (5) Co-op Energy 22% (63%) 22% (30%) 56% (7%)
14 (11) Scottish Power 20% (17%) 25% (25%) 55% (58%)
15 (n/a) Extra Energy 18% (41%) 17% (21%) 65% (39%)
Order calculated by 0 points for poor, 1 for OK and 2 for great. 7,782 votes in total – we've ignored providers with fewer than 100 votes. We've also excluded Telecom Plus/Utility Warehouse because it's a network marketing company, meaning its customers also spread the word and sell the product, which can positively skew its votes. The percentages may not add up to 100% due to rounding.

'It's easy to ditch, switch and usually save'

Martin Lewis, founder and editor of, says: "It's a shame for Co-op, which obviously had a great history as a mutual brand, to see it plummet down the customer service tables like this.

"Yet it's a lesson for all companies; don't change your system until you're sure it works. It takes years for companies to build trust, but this shows you can destroy it in minutes.

"All energy customers need to remember this is a fluid market, and if you're not happy with where you are, it's easy to ditch, switch and usually save."

'Significant issues with our billing system'

A spokesperson from Co-op Energy says: "We are acutely aware that our normally high customer service standards have slipped over the past few months as we implemented a new customer service and billing system.

We are very sorry to any of our customers that have been inconvenienced and are working incredibly hard to put things right and provide the levels of service our customers deserve. This new system has been put in place to support a continuation of our rapid growth over the past four years."

Ben Jones, managing director of Extra Energy, says: "We are a rapidly growing company, and sadly some customers will experience problems as we grow. We fully acknowledge that a small minority of our customers have not had the level of service they deserve.

"That is unacceptable, and we can and must do better, because one customer complaint is one too many. That is why we are acting on feedback from our customers and changing our systems to allow more regular billing.

"Our company is built around serving people, and we work hard to fix problems when they do occur. We are constantly listening to our customers and learning from them. We welcome their feedback, because it makes us better."