December proved to be a productive month for challenger energy suppliers, with a 35.4% switching rate away from the UK’s six biggest providers, according to comparison site Comparethemarket.

The company’s latest Energy Snapshot showed that switches to the ‘Big Six’ suppliers – British Gas, EDF, E,ON, Scottish Power, SSE and npower – only totalled 10.9% during the month.

E.ON saw the highest number of customers switching to other suppliers at a rate of 21.3%. It was able to plug this gap by attracting new customers – with 19% of switches to the provider recorded.

However, things weren’t as positive for Scottish Power and SSE.

“Whilst E.ON largely plugged its leaky customer bucket via new customer acquisitions, Scottish Power and SSE lost customers without adequately replacing them,” explained Peter Earl, head of energy at comparethemarket.

For example, switches from Scottish Power totalled 14.7%, while SSE saw 11.8%.

During the month, npower also lost customers with a switching rate of 8.4%, followed by EDF Energy at 8.2%.

The winners

In contast, smaller players So Energy and Avro Energy attracted new customers.

For example, So Energy provided two of the five highest saving tariffs in the month. Its ‘So Ox – Green – Seasonal Payments’ resulted in an average saving of £158.57 and attracted 4% of switches, while its ‘So Penguin – Green – Seasonal Payments’ provided an average saving of £155.06 and attracted 7% of switches.

Meanwhile, Avro Energy’s ‘Simple and Exclusive’ tariff claimed third spot with an average saving of £124.83, attracting 7.8% of switches.

“Interestingly, the five highest saving tariffs in December were all from non-Big Six suppliers, serving as a reminder that there is still a lot of price competition in the market. It also suggests that talk of the demise of smaller suppliers may not be putting people off,” Earl added.

Following the collapse of a number of smaller providers, including Economy Energy most recently, Earl noted that many people have not been put off by these events and are happy to switch to smaller providers.

British Gas claimed the most popular tariff overall during December. Its Energy Plus Protection January 2020 attracted 11.8% of total switches, saving customers an average of £71.30. It was followed by E.ON’s fix two-year exclusive December 2018 offer, which resulted in an average saving of only £7.50.

The data precedes the introduction of the energy price cap, which came into force at the start of the year. It applies to default tariffs and aims to prevent energy providers from charging more than £1,137 for a typical duel fuel tariff. The cap will be in place until 2020 and is likely to rise in April.