One of the Big Six energy providers has apologised to customers affected by its malfunctioning smart meters charging them as much as £33,000 for a day's power.
A glitch with SSE's gadgets, which tracks a household's energy usage, warned one consumer they had bust their daily budget by nearly three million per cent.
Complaints began appearing on the company's Twitter page on Friday, with dozens of customers saying their meters were quoting thousands of pounds for 24 hours of gas and electricity.
The energy giant has launched an investigation into the errant devices.
Shocked account holder Mark Umpleby tweeted SSE with a photo that said he had used £33,183 of gas in one day - 2,765,175 per cent over budget.
The following day the meter said the bill would be £27,022 for the day. The average annual bill for a medium-sized house in the UK is around £830.
He said: "Prices certainly gone up @YourSSE @SSE if my smart meter is accurate on my gas use over last few days! like it warm but .."
I think there's an issue with my "smart" meter. pic.twitter.com/gFw83f74Qq— Absolutely Wild (@absolutelywild) March 4, 2017
Another customer, Usman Hussain, tweeted a picture of his meter saying he would be charged nearly £9,600 for his day's electricity and gas.
SSE said it was aware of an issue affecting "a small number" of its smart meters.
A spokesman said: "The issue will be investigated as a matter of urgency and no customer will be charged the extra amounts resulting from errors with the smart meters.
"We would like to apologise to any customers if this has caused distress."
Smart meters communicate directly with energy suppliers, allowing customers to monitor their energy use in real-time and eliminate the need for estimated billing.
The Government hopes the devices will be rolled out to every home in Britain by 2020. The latest figures show there are 4.9 million meters in homes and businesses across the country.