Millions of people may not receive their salaries on time this month due to IT error

Firms have reported payroll errors after software was affected by a global IT outage. The IT disruption led to queues and delays at airports, disruptions to GP services and payment failures in some shops.

Cybersecurity firm CrowdStrike is “actively working” to fix a “flaw” in an update for Microsoft Windows users that triggered the outage. Workers who are paid weekly could also be affected by the outage, after companies said their payroll software was also affected.

Melanie Pizzey, chief executive and founder of the Global Payroll Association, said: “We have already been contacted today by numerous customers who have been unable to access their payroll software due to the Microsoft outage and others who have been prompted to log out . with immediate effect.

“Depending on the length of this disruption, it could have very serious implications for businesses across the country, particularly those that process payroll on a weekly basis. In addition, we may experience a delay in processing payroll for the end of the following month, which may delay employees receiving their monthly salary.

“At best, it will require people handling payroll to work overtime to fix the problem, but the good news is that it doesn’t appear to be a cyber attack.”

Some banking services were also affected, with Barclays bank reporting that its digital investment platform was also experiencing disruptions. A spokesman for the bank said: “All Barclays services are operating as normal at this time, with the exception of our digital investment platform Smart Investor, where customers are unable to manage their account in the app, Online Banking or over the phone.”

Other payment services, banks and financial institutions have tried to reassure customers that their systems are working without interruption. Link, which runs the UK ATM network, said its network was “operating as normal but enhanced monitoring is in place as a precaution”.