Millions of NatWest bank customers faced financial trouble this weekend after technical glitches left angry clients unable to pay bills, access their accounts, and even receive their wages.

The upheaval extended beyond the bank's customers, with the Guardian website reporting that one couple who do not bank with NatWest were unable to move into their new home because of the glitch.

Customers at Royal Bank of Scotland (RBS) and Ulster Bank were also affected. All three banks are part of the RBS Group.

NatWest left more than 900 branches open until 6pm on Saturday, with plans to open them again until midday on Sunday as it works to clear the backlog.

The bank claims the glitch has been fixed, and has apologised to customers. It also moved to assure users that anyone incurring penalty charges as a result of the glitch would be compensated.

NatWest has more than 7.5 million personal banking customers, but said there was no way to tell how many of them had been affected.