A technical problem has hit banking giants RBS and NatWest, affecting some customer accounts online.
RBS told Sky News in a statement: "We are currently experiencing technical issues which mean that a number of customer account balances have not yet been updated and some of our online services are temporarily unavailable.
"We are working hard to fix this and hope to have the problem resolved as soon as possible. We apologise for the inconvenience caused to our customers."
The technical issue has also caused problems for customers and staff in some local branches.
A Sky source said a large group of people had gathered outside a NatWest branch in Reading after failing to access their accounts.
RBS and NatWest, both part of the Royal Bank of Scotland group, share a number of technical systems, including online infrastructure.
Last week the banks started a smartphone banking service to allow customers to withdraw money from cash machines.