RBS is said to be considering legal action against CA Technologies, following the debacle of the past week which left millions of customers unable to access their funds.
A software failure in the banking group’s IT systems stopped customer account balances from being updated, meaning users of RBS, NatWest and the Ulster Bank found banking services were unavailable.
Customers could not withdraw money paid into their accounts from Thursday onwards.
As a result thousands of bills went unpaid, numerous credit scores were damaged and customers faced uncertainty as to when the problems would be rectified.
Computer Weekly was the first to confirm the RBS technical fault came from CA Technologies' software. Rumours are rife that it was an overnight software update for the company’s CA7 batch process scheduler, used by RBS’ back-end systems to update account balances.
Now, the Financial Times has cited two sources familiar with the situation as saying the banking group’s board was yesterday debating whether to take legal action against CA Technologies for the trouble its software has caused.
“It was certainly an issue with this software,” said one source. “We will still have to establish if this was their fault or if it was our handling of the software.”
A spokesman from RBS would not confirm the discussion. He told Computer Weekly: “We have been clear we will fully investigate the causes of this incident.
"But we hope people will understand that right now our complete focus is on fixing this problem and helping our customers."
Computer Weekly contacted CA Technologies for comment but the software supplier has yet to return the request.
Although RBS claims to have fixed the problem and caught up with 99% of the backlog, this could still leave 150,000 customers without the correct balance and access to funds paid into their accounts.
RBS has promised to cover any charges faced by customers for missing payments.
CEO Stephen Hester told customers on Sunday: “No-one will be left permanently out of pocket as a result of this and they should contact us directly.”