How the scores are worked out
We compare energy suppliers' customer service by looking at data from a number of reliable sources. We publish data about suppliers with more than 25,000 customer accounts.
Data about complaints to third parties
We base our ratings on complaints made to:
Citizens Advice Consumer Service
the Extra Help Unit
the Energy Ombudsman
Data about billing, customer service and switching
We use data from suppliers to determine the following:
Customer service - the average call centre wait time (excluding time spent in automated systems, and dedicated sales lines)
Bill timeliness - the proportion of bills and statements which are sent within 15 days of when they were due
Bill accuracy - the proportion of customers who got a bill based on a meter reading in the past year (excluding prepayment customers)
Switching - the proportion of switches completed within 21 days of the contract being agreed with the supplier
Data about customer guarantees
There is publicly available data on membership of the following schemes:
We also check with suppliers if they are certified for the British Standard for inclusive service provision (BS 18477) .
If we don't have data for your supplier
Suppliers are legally required to share the data we use in this rating. They also need to have a referral system to our consumer service.
If they don’t, we score them zero in categories related to these things.
We need suppliers to give us permission to publish data they share with us. If they don’t, you’ll only see a star rating.
How we come up with a star rating
We give energy suppliers a score out of 5 for each category. 1 is poor and 5 is excellent. Then we give them an overall star rating out of 5.
|Number of complaints per 10,000 customers||5 or less||5 to 15||15 to 30||30 to 55||More than 55|
|Average call centre wait time (seconds)||Less than 30s||30s - 90s||90s - 180s||180s - 300s||More than 300s|
|Switches completed within 21 days||More than 98%||95-98%||90-95%||80-90%||Less than 80%|
|Customers who had accurate bill in the past year|
|Bills and statements sent on time|
Suppliers score 3 points for membership of the Energy Switch Guarantee, and one point each for membership of other schemes (up to a maximum of 5 points). Trial members of the switch guarantee score 2 points.
Not all categories are equal. Some, like complaints, count more towards the final score than others.
This is how we work out the overall scores.
|Category||Measured as||Counts towards overall score|
|Complaints to third parties||Complaints to third parties||35%|
|Customer service||Average call centre wait time||20%|
|Switching||Switches completed within 21 days||15%|
|Customer guarantees||Membership of a range of schemes||10%|
To measure bill accuracy, suppliers must have been supplying more than 5,000 customer accounts for 12 months. Suppliers with less than this are scored on bill timeliness only.
Some suppliers have mostly customers who pay by prepayment. Suppliers with fewer than 5,000 billed customers do not receive a billing score, and are scored on the other categories only.