The energy bills are rising by £1849 in the UK from April 2025; therefore, it is important to choose the right supplier to save your money. Many households focus on switching to the cheapest energy deals. But before switching your supplier, it is important to know which companies to avoid. The companies with poor customer service, frequent billing issues, or a history of complaints are ones to avoid. We have created a data-driven, in-depth look into the top 10 worst energy suppliers in the UK for 2025. This review is based on customer satisfaction, complaints, and independent reviews.
There has been a lot of service-related news about energy suppliers all over the UK for the past couple of years. These were about supplier collapses, price hikes, and customer service scandals. Poorly performing suppliers can leave you with:
The majority of UK suppliers, about 92%, are on variable tariffs, and the average bill under the price cap is £1849. It is important to avoid the worst suppliers to save money and stress.
Why they’re on the list: Utilita has received the lowest customer satisfaction scores; there are a lot of complaints about billing errors, confusing prepayment systems, and poor support. They are receiving a lot of complaints compared to the money you are paying them.
Common complaints:
Why they’re on the list: They are the UK’s largest suppliers. But they also have very high complaint rates. These complaints are regarding billing, metering, and customer support. Their frequent issues also include long call wait times and an opaque tariff structure.
Common complaints:
Why they’re on the list: Rebel Energy collapsed and was unable to provide its service to its customers in early 2025. This left many customers stranded and transferred to other suppliers. Even before the closure, customers complained about instability and poor service.
Common complaints:
Why they’re on the list: This is also one of the biggest suppliers in the UK; they have one of the highest numbers of complaints per 100,000 customers. They also face criticism for poor complaint handling and long wait times, despite recent investment in customer service.
Common complaints:
Why they’re on the list: Yes, they are often praised for their innovation, but they couldn’t always keep up with rapid growth, which led to inconsistent service for some, billing errors, and a high volume of complaints relative to some other large suppliers.
Common complaints:
Why they’re on the list: This is one of the companies that scored among the lowest for customer satisfaction in a survey conducted in 2025. Customers have reported price hikes, poor value, and slow complaint resolution.
Common complaints:
Why they’re on the list: They have recently seen their customers' trust erode with lower customer satisfaction rates. Complaints include limited support (especially on weekends), expensive variable tariffs, and a slow switching process.
Common complaints:
Why they’re on the list: This is another supplier that has reportedly scored low for satisfaction rates, with frequent complaints on hidden fees, smart meter rollout failures, and poor complaint handling.
Common complaints:
Why they’re on the list: This is another company that struggles with slow customer service, unclear billing, and inconsistent complaint resolution, resulting in a below-average satisfaction score.
Common complaints:
Why they’re on the list: If you ask about this company, they lack transparency, have faced disconnection errors, and show weak customer commitments. They have received complaints about sudden disconnection and a lack of clear information about their services.
Common complaints:
| Supplier | Customer Satisfaction | Complaints per 100k | Major Issues |
|---|---|---|---|
| Utilita | 1.9/5 | 671 | Billing, payment difficulties |
| EDF Energy | 2.4/5 | 1,361 | Billing, delays |
| Rebel Energy | 2.4/5 | N/A | Collapse, instability |
| British Gas | 2.9/5 | 1,427 | Service, complaints |
| Octopus Energy | 2.9/5 | 1,841 | Billing, delays |
| OVO Energy | 2/5 | 2,009 | Value, communication |
| So Energy | 1/5 | 1,043 | Support, tariffs |
| ScottishPower | 2/5 | 1,227 | Fees, complaint handling |
| Co-Operative Energy | 3.1/5 | N/A | Delays, unclear billing |
| TruEnergy | 2.6/5 | 540 | Transparency, disconnections |
If you have gone through the above, you may have noticed that there are some common complaints every company has received. To sum it up: billing errors, long call waiting times, slow complaint resolution, smart meter and prepayment problems, and a lack of transparency. Therefore, we advise you to make sure the company you're choosing doesn’t have these errors, even if they are not listed above.
Even if you are stuck with a poor energy supplier, there are actions you can take: raise a formal complaint (they should respond within eight weeks), contact the energy ombudsman, and switch suppliers once any exit fees are covered. Switch Squid is always ready to help you with the switching process.
The energy price cap is rising in the United Kingdom. And it may continue to fluctuate in future years. Therefore, it is important to avoid the worst energy suppliers and find the cheapest deal. Stay informed using independent comparison tools to support yourself with a good energy supplier.
For more guidance regarding comparison and switching, explore the helpful guides at Switch Squid.
