The issues began about 8am, with users taking to both social media and website outage monitoring website Downdetector to complain.

Tweets posted by TSB customers included:

“@TSB Can’t log in like many others. Sort it out, bills to pay.”

“@TSB Your bank is beyond a joke. Can’t use app or internet banking this morning. Today, I will be switching my account to someone else.”

“@TSB is there an issue logging on to internet banking? Website giving this error code: ERRSCA02. Can you help?”

According to Downdetector.co.uk, TSB’s issues started at about 6.30am this morning with a peak in reported problems at about 8am.

One TSB customer posted on Downdetector: “Still not working, got through to call centre after 50 minutes, agent said was a major incident. She said internet banking is working. When I launch the app it’s asking for my ID, basically to register. After tracking down my ID, it still doesn’t work. Internet banking won’t let me login, it goes back to login screen.”

A TSB spokesperson said: “A number of our customers experienced difficulties logging into their mobile app or the internet at the start of the day. The issue was quickly addressed, and all our services are operating normally.”

The problems occurred just days after TSB announced it was closing 164 branches to focus on online banking.

TSB was plagued by IT issues in 2018 after an IT upgrade left up to 1.9 million customers locked out of their accounts. The problems went on for several weeks with customers also unable to contact the bank by phone.

The fiasco cost TSB a total of £330m for customer compensation, fraud losses and other expenses.