Martin Lewis has issued a new alert for people to check their  state pension forecasts, and more than 100,000 could be owed money from HMRC.

The issue stems from missing Home Responsibility Protection credits on people’s records, which happened because of a system error during the switchover to National Insurance credits. People who have missing credits will not be receiving, or be on track to receive, the correct amount of state pension, and could be falling thousands of pounds short.

Sharing a new video snippet from his podcast, the Money Saving Expert founder said: “This is an important heads up about a state pension error that mainly affects women between the ages of 40 and 90, and especially those in their 60s and 70s.

“It’s for people who took time off work between 1978 and 2010 to look after their children or care for someone who is long-term disabled.

“You were meant to have got a thing called Home Responsibilities Protection, which should have given you National Insurance years to replace the ones you weren’t getting by working, and you need those National Insurance years to get a full state pension.

“But it’s possible that over 100,000 women didn’t. While the Government had been trying to contact those women, it has stopped doing so now. So, the onus is on you.”

HMRC was previously contacting those affected, reportedly writing to more than 300,000 people.

However, in a new annual report, the Department for Work and Pensions (DWP) significantly reduced the funds allocated for repayments from £1.2 billion to just £29.8 million. This change is attributed to a low public response to requests for people to check their records and claim the missing credits.

The report reads: “Correcting HRP is inherently challenging. The number of people applying to correct their missing HRP has been low. Substantial numbers of people have not responded to the Government calls for them to apply to add missing HRP, and the exercise has resulted in much lower activity levels.”

Mr Lewis continued: “To show you how big this could be, Cilla got in touch with me and said, ‘I’ve just received 15 years’ back pay from HMRC of £31,674 for underpayment of my state pension. Thank you.”

Sharing the next steps to take, Mr Lewis said: “Go on to Welcome to GOV.UK to see if you’re projected to get the full state pension. If you’re not, you need to see where your gaps in years were.

“Were they between 1978 and 2010? If so, were they years where you were not working to look after your children or someone who had long-term disabilities? If they were, you need to go and do your research on Home Responsibilities Protection because you could be owed money.”

To receive the full new state pension, people typically need around 35 National Insurance contributions, but this number varies, and some people need more.

You can check your NI record online or using the free HMRC app. The quickest way to claim missing HRP credits is online, though support is also available by calling the National Insurance helpline on 0300 200 3500.

To apply, individuals must complete form CF411, available on the Government’s website. Once approved, HRP credits can be added retroactively to an NI record, potentially increasing pension entitlements and triggering back payments.