Six in 100 state pensioners were underpaid last year, new figures show. The error rate for 2024/2025 is up from five in 100 the year before, according to the data from the Department for Work and Pensions (DWP).

Former pensions minister Sir Steve Webb warned some people could be thousands of pounds out of pocket. Sir Steve, partner at pension consultants LCP, said: “It is astonishing that six in every hundred state pensioners are being underpaid.

"In some cases these underpayments have been going on for years and could amount to thousands of pounds.

"When people have worked hard all of their lives, they have a right to expect that their pension will be paid at the correct rate.

"Given how complex the system is, it can be hard for people to know if they are getting the right amount or not, so it is all the more important that the Government gets it right.

"You would have hoped that all of the recent correction exercises would have resulted in a falling rate of errors, so it is all the more shocking to see underpayment rates increasing.

"DWP need to redouble their efforts to track down these errors and fix them as a matter of urgency."

One of the main sources of underpayments is mothers who were wrongly getting no National Insurance credits for time at home raising a family.

The issue arose when people claimed child benefit before 2000 when they did not need to put their National Insurance number on the claim form as the credits were not added to their record.

The rise in errors also comes despite the completion of a four-year correction exercise which paid out over £800million in arrears to over 100,000 widows, married women and over 80s.

The DWP has been contacted for comment.