The shortfalls were due to errors with the Home Responsibilities Protection (HRP) scheme, which was designed to protect the state pension rights of parents — mainly mothers, who left work or reduced their hours to care for children.

HMRC failed to correctly record HRP entitlement in some cases, resulting in underpaid pensions for affected women, many of whom were aged 60 to 79.

Pension reclaim firm AskRose, based in Greater Manchester, which represents as many as 100,000 affected women, says dozens of clients have died during the claims process.

Elaine Walker, director of AskRose, said: “While we welcome HMRC’s belated decision to allow approved and vetted reclaims specialists to assist these elderly claimants, we really hope that they can keep the process as efficient as possible for the sake of the women involved.

“In the time it has taken for them to open this process up, too many of our clients have sadly passed away before being able to claim the money they were owed.

“They were left, in some cases, for more than 15 years without a fair pension and were then unable to even enjoy getting their recompense.

“These are the people who cared for the younger generations and are now suffering because of a government error.

“They brought us up; the least that we can do is make sure they don’t get punished for that in their dotage.”

Of the women now able to claim, most are aged between 60 and 79.

With an estimated one in 10 women, more than 55,000, in that age group dying each year, campaigners fear many have died without ever receiving the payments.

The government set aside £1.2 billion for repayments, with each claim worth an average of £8,377.

In 2023, HMRC wrote to affected pensioners in an effort to raise awareness of the issue, but the response rate was only eight per cent, far short of the expected 90 per cent.

The HRP scheme operated before 2010 and reduced the number of National Insurance qualifying years needed for a full state pension.

Eligibility included people who claimed Child Benefit for a child under 16, those who were the partner of a Child Benefit claimant while acting as the main carer, people receiving Income Support as a carer, and those caring for someone who was sick or disabled and receiving certain benefits.

Those concerned about their eligibility can call HMRC on 0300 200 3500, use the government’s online tool, or contact AskRose.

The company charges a small percentage of the back payment but does not take a share of future pension payments.

More information can be found here: https://www.askrose.co.uk/1/v1/1-landing