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A note to readers:

As of 1 November 2020, we have updated our Supplier Types to reflect Ofgem’s new designations: Large (a Supplier with five percent or more market share), Medium (a supplier with between one and five percent market share) and small (market share of less than one percent). This means we have revised our previous approach and no longer refer to the Big Six.

Ofgem’s new designations came into force from the end of November, and the agility of the Energy Market Data Hub (EMDH) insights has enabled ElectraLink to change its reporting so rapidly.

Additionally, as of 1 November, in our monthly switching updates we have changed the way we manage the switches between distinct Supplier brands owned by the same company (e.g. SSE/Ovo and E.On/npower). All intra-group switches will be excluded, as Ofgem now include SSE’s old customers in Ovo’s market share. Previously, we have only excluded switches where there was significant portfolio re-organisation happening. This was to try and accurately reflect real world customer behaviour, as the average consumer is unlikely to be interested in the intricacies of Supplier company ownership.


Data from the EMDH published today shows changes of supplier (CoS) in November 2020 slumped compared to the month before.

537,000 switches were completed – 15 percent less than October 2020, although data from previous years suggests this is an expected trend. However, changing supplier is still increasing on an annual basis as November 2020 marked an increase of seven percent compared to November 2019.

The combination of these two data points leads us to believe that CoS activity remains healthy and end users increasingly acknowledge the benefits of changing supplier.

The year to date has recorded 5.69mn CoS completed – two percent less than January-November 2019, largely due to the severe impact of COVID-19 lockdown measures which affected switching earlier in the year.

Chart showing switches completed for the GB energy market

CoS started also dipped in November, England’s strict lockdown potentially influencing end user switching behaviour. 612,000 CoS were started – 13 percent less than the month before and one percent less than November last year. While the lockdown might have impacted CoS started in November, it did not have the same level of impact on customer switching behaviour as we saw in Spring.

Chart showing switches raised for the GB energy market

In terms of CoS types, where our insights and supplier designations previously showed the most popular type of switch was from Big Six to challenger brands, incorporating the new Large suppliers designation means Large-to-Large switches are now the most common. However, Large-to-Other switches remain the second most common, demonstrating that the Small and Medium Suppliers are just as attractive to customers as their more established competitors with larger advertising budgets.

  • Large to Large switches reached 228,000 – 11 percent less than November 2019 and 42 percent of November 2020’s total switches completed,
  • Large to Other switches reached 164,000 – 51 percent more than November 2019 and 31 percent of November 2020’s total switches completed,
  • Other to Large switches landed at 81,000 – 13 percent less than November 2019 and 15 percent of November 2020’s total switches completed,
  • And Other to Other switches hit 64,000 – 36 percent more than November 2019 and 12 percent of November 2020’s total switches completed.

Further investigation into the data reveals the Supplier Type Net Gains/Losses, still excluding trade sales and Supplier of Last Resort events. Activity over the past few years suggests customers are more likely to switch to Small and Medium Suppliers than to large, as Large suppliers have predominantly experienced net losses.

For more information on CoS figures, contact [email protected]. If you would like access to the CoS data we hold and analysis we provide for the energy market, please reach out to [email protected].



The above figures relate to electricity CoS in Great Britain only.

We do not include CoS from Supplier of Last Resort (SoLR) processes or trade sales in our monthly CoS reporting. We account for only voluntary switches, or instances where the customer made an active decision and took action to change supplier.

CoS started refers to the number of valid switches started, also known as CoS raised.

All data is provided by ElectraLink’s Energy Market Insights (EMI) from the EMDH.

ElectraLink has been granted the governance protections to hold, transfer and analyse CoS and other data.