Thousands of hourly paid employees were affected by the glitch, according to an internal memo to senior staff.

Union bosses have alleged some staff were underpaid due to the glitch. 

The payroll issues follow a company wide IT update.

The new IT system was tested for the first time this week as the supermarket giant implemented a new form of payment software.

Dubbed "Project Future," the new payment software is being rolled out after billionaire brothers Mohsin and Zuber Issa bought the company for £6.8bn in 2021.

In an internal memo to store managers, Asda bosses said: "During our payroll checks, we have currently identified around 9,500 hourly paid colleagues who are impacted by incorrect pay, due to what we believe is an issue with a specific holiday calculation as we have moved to our new systems.

"Colleagues' payslips may not show correctly so please reassure colleagues that we are aware of this and are making the relevant adjustments to ensure that colleagues receive payment by Friday payday."

An Asda spokesperson told the Telegraph that the company had recently launched a new HR system and "conducted pre-emptive checks to identify any potential issues before colleagues were paid this month."

"These checks found a potential problem with holiday pay that could have resulted in a pay discrepancy for some hourly paid colleagues. We have taken immediate and proactive steps to correct this – to help ensure there will be no shortfall in pay for these colleagues this month. Project Future will give Asda a world-class IT platform," the spokesperson said. 

CloudPay CCO John Pearce said that making correct payments on time is not just an expected element of day-to-day operations, but also a moral objective for companies. 

"That fact that it was overtime payments that were missing from pay packets suggests that both the legacy system and the new platform weren't geared up to manage last minute additions to payroll," Pearce said. 

"This isn't the first time that the brand has had similar payroll difficulties so the damage that this could have on Asda's employer branding is significant and will be difficult to reverse," he added. 

UK bank Nationwide confirmed it had suffered an IT glitch on Friday (22 March) which left a number of payments delayed. 

The glitch occurred when planned overnight maintenance took longer than expected, according to the bank. 

Last week, Sainsbury's, Tesco, McDonald's, and Greggs also suffered IT glitches, which led to store closures, payment failures, and delivery issues. 

All of the retail chains have been vague on details about what caused the glitches, with all of them blaming the issue on software updates.