By Don Quijones of Spain, the UK, and Mexico, and editor at Wolf Street. Originally published at Wolf Street

Internet banking has become a crisis-prone business in the UK, as the online platforms of big banks suffer regular outages and other forms of IT disruption.

Friday morning, the online systems of the Royal Bank of Scotland, Ulster Bank and Natwest — all part of the RBS Banking Group — crashed in unison, leaving millions of customers unable to pay bills or view their balance on their online and mobile accounts. The group has 19 million customers in the UK and Republic of Ireland and 5.5 million active mobile app users.

After around five hours of chaos, the RBS Group announced that the problems had been resolved. The failure had apparently been caused by a “technical glitch” — a word that is being used with increasing frequency by high-street lenders — in a regular update to their firewall. The bank emphasized that it was an “access issue” and there is no evidence that customer data was compromised. But then, it would say that!

On Thursday, it was the turn of the UK’s largest bank, Barclays, whose website and telephone banking service crashed for around seven hours, leaving frustrated customers locked out of their online accounts.

Fed-up customers took to social media to vent their anger, with some complaining that they were unable to access their accounts not only through the Internet platform but also ATMs. Barclays has around 24 million UK customers, though it’s not clear how many of them were affected by the outage.

The bank told customers that they should still be able to make payments to existing payees through mobile banking, though new payees weren’t possible due to the incident. It also claimed that payments into accounts were unaffected by the issues.

One alarmed customer begged to differ, complaining to the BBC that a payment due into his account had gone missing, while another customer reported the systems inside branches being down, preventing customers from carrying out transactions even in the old fashioned, pre-digital way. By mid-afternoon, the IT “glitch” — that word again! — had been “resolved,” though no explanation has yet been given as to what caused it.

A few days earlier an outage at online challenger bank Cashplus, which targets people with poor credit histories, left customers unable to access their accounts, make cash withdrawals, or make or receive payments. The problems prompted Nicky Morgan, chair of the Treasury Committee, to ask Richard Wagner, chief executive officer of Cashplus, for an explanation of what happened and how victims of the outage will be compensated.

In other words, over the last two days, dozens of millions of UK bank customers have been locked out of their online accounts at different banks.

In terms of RBS, this is not the first time this year its subsidiary Natwest has suffered an outage. Its banking app went down briefly in April and in July a glitch with its card payments left customers unable to use their cards in shops or online.

RBS, the largely state-owned lender that has cost British taxpayers almost a hundred billion pounds in bailouts, losses, fines and legal fees, also has a rich history of outages, including a major blackout in 2012 that lasted for over a week, disrupting customers’ wages, payments and other transactions. The outage was allegedly caused by an “inexperienced” RBS tech operative’s blunder. For the duration of the blackout, the only means many customers had of accessing basic banking services was to visit the local branch.

That, however, didn’t stop RBS from embarking on a branch closure rampage, blaming the growth of internet banking for its decision to close one in four of its branches. Now, it can’t manage to keep those web-based services up and running, leaving customers even worse off. Even as the lender has increasingly digitized its services, it has consistently downsized its IT services team. In 2017 it revealed that it planned to axe 900 IT jobs by 2020 and is doubling down on its outsourcing of IT roles to India to reduce costs.

This underscores one of the major problems high-street lenders have with technology. They never treat it as a mission-critical aspect of their business, even as that business becomes increasingly dependent on technological solutions to stay competitive.

Bottom line-obsessed bank executives are always looking for cheap, short-term shortcuts to IT issues, with the result that lenders — particularly, but not only, in the UK — have for decades under-invested in their sprawling, creaking, accident-prone legacy systems dating back to the primeval age of COBOL and mainframe technology. And if some banks had been thinking about trying to finally move off their legacy systems and drag their IT platforms into the 21st century, the recent botched IT migration at mid-sized TSB, which continues to sow chaos 23 weeks after it was supposed to be ready, will not encourage them to do so.

Time is running out. March 29 is the deadline. Urgent action is needed. But it’s not happening. Read… Disorderly Brexit Would Trigger Mayhem in Derivatives Market