The energy firm was found to have failed in three separate areas between 2017 and 2020, affecting around 61,000 customers.

Energy regulator Ofgem found that 3,800 consumers were blocked from switching to Bulb, missing out on savings. This is because these customers were on Restricted Meter Infrastructure (RMI) where there’s more than one meter at a property.

Bulb submitted incorrect meter data to the supplier consumers wanted to switch away from so the switch couldn’t go ahead. Due to this error, Bulb paid £155,500 to the consumers affected.

In another area, 11,400 RMI customers were wrongly charged multiple standing charges, and were overcharged by nearly £700,000. Ofgem said Bulb has paid back affected customers and made goodwill gestures totalling £675,000.

Further, around 46,500 vulnerable Bulb customers were removed from their network operators’ Priority Service Register between March 2019 and January 2020 after a system error.

This resulted in some customers missing out on essential services, such as being given advance notice of a planned power outage. Bulb reported this error to Ofgem earlier this year and compensated 933 customers who suffered a power outage. This totalled £70,000.

Bulb paid a further £157,000 into the voluntary redress fund to support vulnerable customers.

Ofgem said Bulb “had insufficient processes in place to review and prevent non-compliance” which contributed to the failings.

But it noted that Bulb confirmed it has improved governance and processes and it has now closed this compliance issue without taking enforcement action.

Ofgem’s CEO, Jonathan Brearley, said: “Bulb overcharged some customers, and risked leaving vulnerable customers without access to essential network services, when it failed to comply with Ofgem’s rules.

“Our rules are designed to protect consumers, and suppliers must make sure they have the processes in place to comply with them if they are going to give their customers good service.

“Bulb has since put things right with affected customers and put processes in place to make sure it can meet Ofgem’s rules.”

A Bulb spokesperson, said: “We recently fixed some issues which affected some of our members and potential members. At Bulb, we pride ourselves on the quality of our operations and technology, but we know there will always be ways we can keep improving. That’s why we’ve strengthened the Bulb team, boosted training, and put in place even more rigorous checks and verification processes.”