RBS suffereed a computer glitch on Monday evening, leaving customers unable to use their debit cards or log in to internet or mobile banking. The problems happened on what was expected to be the busiest online shopping day in the run-up to Christmas, dubbed Cyber Monday.
What went wrong?
Between 6.30pm and 9.30pm customers found they were unable to make payments or withdraw money from ATMs with debit cards, or were unable to log in to the bank's online banking or mobile systems to check balances or make payments.
RBS says it is unclear why everything stopped working, but Susan Allen, director of customer solutions at RBS, said investigations suggested it was "completely unrelated" to a rush of people using cards on Cyber Monday.
The bank's chief executive, Ross McEwan, has described the systems failure as "unacceptable" and apologised to customers.
Who was affected?
Customers at the bank's three brands, RBS, NatWest and Ulster Bank. RBS said it would usually expect about 250,000 withdrawals an hour on that period of a Monday evening, so around 750,000 people are likely to have been thwarted in their attempts to take out cash. It does not know how many payments were declined over the period.
Are the problems fixed?
The bank said the problem lasted three hours and has been rectified, but on Tuesday morning some customers were still reporting difficulties logging into the banks' websites and that their balances were not showing correctly.
I couldn't fill up my car and had to get a taxi. Will I be compensated?
You should be. RBS has said it will make sure customers are not out of pocket as a result of the failure. Compensation will be arranged "on a case-by-case basis". To make a claim you need to visit a branch or call the bank and explain that you want to reclaim your money.
I had to ditch my weekly shopping at the checkout. What about me?
There are lots of stories of people being thwarted in their attempts to do their shopping as a result of the meltdown – one man reported rows of full trollies in an Asda store in Newcastle that had been abandoned when people found they couldn't pay, while others tweeted of being unable to pay for online orders. However, RBS said it would not be compensating for inconvenience or time wasted – it is focusing on reimbusing people who incurred costs.
Does RBS have more IT problems than other banks?
It seems to have a lot – most notably the meltdown in June 2012 that left some people locked out of their accounts for days on end and caused problems with payments to and from RBS accounts.
Since then there have been problems at other banks. For example, in October 2012 Lloyds, Halifax, Co-op Bank and Smile customers were unable to access cash one afternoon. But RBS has also had other issues, and on Tuesday McEwan admitted that "for decades, RBS failed to invest properly in its systems".
I've had an email telling me my security details have been reset. Why?
Because there is already a phishing scam on the go, aiming to trick customers into giving away their security details. Don't click on the links in any email purporting to be from the bank. If you have done and have concerns, or you have received a different email and are unsure if it is legitimate, call the number you usually use to make sure.
