The email titled “pre-collection notification” was sent yesterday morning and threatened customers with late payment fees and “service restrictions” if they didn’t make a phone or online payment.

But when customers checked their bank accounts, they found their bills had been paid by direct debit as normal. However, logging into their Virgin Media online account resulted in being told their payment was overdue.

The email said: “We’re getting in touch because you’ve only paid part of your Virgin Media bill” and then stated an amount that needed to be paid. In some cases the amount was the same as the regular monthly payment paid by direct debit.

Worried customers, many of whom work from home and rely on broadband, tried to call Virgin but were faced with long call waits as the company struggled to cope with an influx of calls.

Those customers who did eventually get through were told the email was a mistake and their accounts were not in arrears.

It wasn’t until after 9pm last night that Virgin emailed customers to apologise for the incident in an email titled “Oops, we sent a payment reminder in error”.

The email said: “Unfortunately, due to a technical glitch, this message was sent in error so please disregard the email. There are no outstanding payments on your account, no additional payments have been taken and no further action is required.”

Virgin Media refused to say how many customers were affected by the error, but scores Tweeted about the issue while more than 60 people replied to a post on Virgin Media’s help forum saying they had the same problem.

A Virgin Media spokesperson said: “We apologise to the small number of customers who received a payment reminder notification from us in error.

“A fix is now in place, and we’ve written to those impacted to let them know what happened, and that no further action is needed.”

Virgin added that no customers saw additional payments taken, services were not disrupted, and that it had put in place additional measures to prevent the issue from happening again.