Square is suffering a major systems outage that has left sellers unable to access their accounts or process payments for more than 12 hours.
The Block unit says that the outage hit at around noon Pacific Time on Thursday and was still affecting clients as of around 4:00am PT Friday.
A disruption at a data centre hit "multiple Square services," affecting sellers as well as Cash App users across the US, although it is not clear how many firms are affected.
In the most recent update on the company's status page, at 5:21 PT, Square says: "Services are steadily regaining their functionality".
"We know you trust us with your business, and these situations add challenges to running your operations. For that, we are truly sorry," says a Square tweet.
By mid-morning Friday, Square had reported that the services sere back up and running.