More than 1.9 million online TSB customers were unable to access their accounts after a botched upgrade to the bank’s IT systems last month.
TSB was transferring over accounts and customer information from a Lloyds system to one designed by its current owner, Spanish lender Sabadell.
The bank was sold by Lloyds to Sabadell in 2015 but TSB continued to pay to use its former owner’s IT systems while it designed a new platform.
Lloyds got in touch with TSB on the morning of April 23 to offer assistance in resolving the issues, the Financial Times reported.
However, TSB turned down the offer.
TSB may have 'hoped to get away with it', says MP
Labour MP on the cross-party Treasury select committee, John Mann, told the FT that TSB’s refusal to accept a hand from Lloyds showed that it failed to acknowledge the scale of the problem.
Mann said it was a sign that TSB may have been “hoping to get away with it”.
“They were playing fast and loose with the customers and also with their reputation, which has been so damaged by it now,” he told the newspaper.
TSB 'calls in the calvary'
TSB drafted in IBM to help resolve the issues almost a week after the IT meltdown began.
The bank’s chief executive, Paul Pester, said he was “calling in the calvary to get this thing fixed”.
But four weeks on from the IT upgrade, customers were still reporting issues with accessing their accounts and transferring money.
In an effort to stop retail and business clients from jumping ship, TSB waived all overdraft fees and interest charges.
TSB has also raised the interest paid out on its standard current account to 5% on balances up to £1,500, up from 3%, for existing customers.