Asda has apologised for underpaying thousands of workers on the first pay day under a new IT system. 

The change in the payment system – part of Asda’s move from Walmart’s legacy IT platform to its own purpose-built one – resulted in workers receiving pay packets today (22 March) without overtime included. Premium rates due for working certain hours were also affected. 

Asda later confirmed holiday pay miscalculations were also behind the underpayments.

Asda told The Grocer it had been working to rectify the problem as soon as possible. By Friday it had processed interim payments to about 3,600 employees out of about 9,500 impacted. 

“Ensuring that our colleagues are paid accurately and on time is our top priority,” said an Asda spokesman.

“We recently launched a new HR system and conducted thorough pre-emptive checks to identify any potential issues before colleagues were paid this month.

“While the majority of colleagues have been correctly paid today, we know there have been pay discrepancies for some hourly-paid colleagues. We have taken immediate steps to address this issue and are making interim payments to rectify any discrepancies.

Read more: Asda confirms some workers may still be waiting for correct pay

“We apologise sincerely to those colleagues affected and for the inconvenience this has caused.”

The supermarket claimed any major retailer with a large number of hourly-paid employees would have such discrepancies in monthly pay cycles, typically arising from failures to accurately record overtime or premium-rate shifts. It said it made on average up to 2,500 adjustments in a typical pay cycle to correct such discrepancies.

It said it had been engaging proactively and collaboratively with union partners including GMB throughout the process.

Read more: Asda announces new staff benefits as pay deal is accepted

GMB said: “GMB understands that many Asda colleagues are experiencing significant issues with their pay this pay day.

“The issue has arisen due to the change in ‘people systems’ used by Asda as they move away from old Walmart systems.”

The union said Asda had “issued significant communications to stores” but the issue had nevertheless caused “stress and anxiety for many Asda colleagues”.

It added: “We hope this is something that Asda can resolve quickly.”

The payment errors follow recent staff walkouts in two Asda stores coordinated by GMB

Asda has been working to disentangle its IT systems from Walmart’s since 2021, following its takeover by TDR Capital and Mohsin and Zuber Issa. Dubbed ‘Project Future’, the supermarket has called it a “once-in-a-generation IT transformation” that promises to give it “a market-leading and sophisticated platform”.