For three hours some of the oil company's sites were forced to close, while card payments were unavailable at others.
The glitch brought chaos to its 1,280 sites across the UK, and the company says a "full investigation" has been launched to determine the cause of the outage.
In a statement, they added: "We will continue to monitor the situation overnight to ensure the smooth running of our operations."
The problems began at about 7pm and resulted in card payments being declined in all BP's stations, forcing a handful of forecourts to close.
One angry Twitter user wrote: "Seriously BP sort your card machines out!
"Everyone is queuing up and unable to pay by card or take cash out to pay for petrol."
As the problem came to light, BP said it was "working to rectify this as a matter of urgency and would like to apologise for any inconvenience this has caused our customers".
Most of the sites were accepting cash payments but a few had shut, it had added.
Just after 10pm, BP tweeted that sites had "returned to normal service and are now once again accepting card payments".
They added: "We would like to thank our customers for their patience and again apologise for any inconvenience caused during the brief outage."