CA Technologies has confirmed that it is working with RBS (Royal Bank of Scotland) on fixing the technical issues that led to an outage of the banking group’s online services for millions of people for five days.

Customers of RBS, Natwest and Ulster Bank were affected by the outage, which led to customers not being able to make payments or see their bank balances online.

RBS has so far said that a technical problem occurred when it carried out a software update on Tuesday (19 June), which it fixed on Friday (22 June).

According to The Register, the RBS’s problems occurred when a failure occurred in its batch scheduling software CA 7 Workload Automation. Although the tool automates some processes, it needs to be maintained and overseen, which is where The Register’s sources claimed that the issues occurred.

Furthermore, a reader comment on The Guardian last Friday claimed that the problem was caused by a “botched ‘upgrade’ to the CA7 batch scheduling suite and the loss of the schedule”.

In a statement, CA said: “RBS is a valued CA Technologies customer. We are offering all assistance possible to help them resolve their technical issues, which are highly unique to their environment.

“We do not comment on customer confidential issues.”

RBS, meanwhile, declined to comment further on CA’s involvement, and, when given an opportunity to point out any inaccuracies with The Register’s report, declined.

“The focus right now is on fixing the problem, which was triggered during a software system upgrade, but we can’t go into any more detail than that at this stage,” the RBS spokesperson said.