State pension news: Married older women could be owed £6,500 EACH

The back payments are estimated to total an average of £6,630.

Women over 80 have also been identified as in arrears averaging £2,710 over the last two years.

However, only 14,512 people from this category are believed to have missed out.

Britons who want to check if they are missing out have been urged to call the pension service on 0800 731 0469.

Earlier this year, a DWP spokesperson said: “The action we are taking now will correct historical underpayments made by successive governments.

“We are fully committed to addressing these errors, not identified under previous governments, as quickly as possible.

“We have set up a dedicated team and devoted significant resources towards completing this, with further resources being allocated throughout 2023 to ensure pensioners receive the support to which they’re entitled.”

Helen Morrisy, head of retirement analysis at Hargreaves Lansdown, warned the DWP still has a “mountain to climb” despite identifying underpayments.

She said: “DWP is making progress in dealing with State Pension underpayments but there’s a mountain still to climb.

“So far almost 47,000 underpayments have been identified with £300million being repaid.

“However, with estimates suggesting as many as 237,000 pensioners have been underpaid £1.46billion it is clear this is a situation that is not going to be resolved any time soon and in the meantime thousands of pensioners are getting less than what they are entitled to.”

She continued: “The issue mainly affects women retiring under the old State Pension system (Basic).

“Some were unaware of the problem but many who queried the issue with DWP over the years were told there was no issue with many enduring real financial hardship as a result.

“These women have been let down on a gigantic scale and need resolution as soon as possible.”