Barclays has been hit by an IT problem that has left some customers unable to access their accounts online or through the app.
On what is the first pay day of the year for millions of Brits, as well as the deadline for self-assessment tax returns, thousands of people have registered problems accessing services on the Downdetector website.
Customers began reporting issues with the Barclays app on Friday morning, with complaints still coming into the bank's social media team well into the evening.
In response to one irate customer at 9:15pm, a bank staffer on X said "we don't have a timescale on when this will be fixed".
On X, Barclays acknowledged customers were having "trouble" with some app features, online banking, telephone support, and payments in and out of accounts - although payments will have gone through.
The bank says cards and cash machines are working as normal, although some customers on social media have disputed this.
With HMRC warning Brits they face a £100 fines of they miss Friday's deadline to file self-assessment tax returns, Barclays says it has been in contact with the tax authority and no customer will be "left out of pocket".