HSBC in London
HSBC has blamed an IT glitch in the BACS system for the embarrassing service failureReuters

HSBC said it has processed almost all salary payments affected by an IT issue at the bank, adding that the remaining ones will be processed overnight. Earlier, 275,000 payments at the bank were delayed due to the problem, leaving many people without cash on payday ahead of the bank holiday weekend.

The bank apologised to customers for the inconvenience on Twitter, adding that it processed 99% of the payments. "Over 99% of payments that were delayed today have now been processed, with the remaining to be credited overnight," the bank said.

It separately released a statement, saying it is committed "to ensuring that no one loses out as a result of today's unacceptable problems." "Customers who do not receive the delayed payment by Saturday morning should speak with their bank in the first instance," the bank added.

It noted on Twitter that the problem arose in the BACS system, which processes electronic payments.

HSBC has informed the Bank of England and the Financial Conduit Authority about the development, according to media reports. Many customers have been angry, as it took very long for the bank to respond to the IT glitch.

"I will be writing to the chief executive of HSBC to obtain an assurance that no customers will lose out from these failures and to ask what is going to be done to prevent a repetition," Conservative party lawmaker and Treasury Committee Chair Andrew Tyrie said in a statement.

Many salaried people complained that they face heavy fines as they were unable to complete mortgage and rent payments on due day. Meanwhile, the bank said it would refund the costs to its own customers and those at other banks, who have been hit by the issue.

The one at HSBC is not an isolated IT issue in the UK. RBS was fined £50m after an IT meltdown in 2012. In 2014, customers of Lloyds and TSB were unable to withdraw money at ATMs or use their debit cards following computer problems.