It is thought tens of thousands of women may currently face being underpaid their state pension, according to research.
Analysis undertaken by the firm Lane Clark & Peacock (LCP) earlier this year showed many were losing out due to a set of complex rules mostly out of their control.
Under the old state pension system, married women were able to claim a basic state pension at 60 percent of the full rate based on their husband’s National Insurance contributions.
However, they were only able to do so if this would be bigger than the pension they would receive based on their own contributions.
However, some women have said they never received such a letter, and have therefore been underpaid.
The DWP is now undertaking a thorough check of its records to determine who has been affected.
But LCP has urged those who think they may have been underpaid to take action immediately.
Although in most instances women have received the amount to which they are entitled, some discrepancies have been noted.
Peter Schofield, the permanent secretary at the DWP, was recently questioned on the matter.
Speaking to the Work and Pensions Select Committee, he said: “I can tell you that we have received almost 11,000 cases. We have reviewed 7,200 of them, and 5,300 of them turned out to be correct.
“The challenge at the moment for us is that we need to work through each of these cases. They are quite complex calculations.”
For those looking to check if they are eligible, LCP has set up an online calculator enabling people to enter details to see if they have been affected.
The firm estimates millions of pounds in back payments could be available to affected women.
Sir Steve Webb, partner at LCP, and former pensions secretary, has set up a petition for the issue to be addressed.
Entitled ‘Review state pension entitlements for all women who may have been underpaid’ it will run until the deadline of March 7, 2021.
At the time of writing, more than 11,000 people have signed the petition, meaning the government will respond to the matter.
At 100,000 signatures, petitions are required to be considered for debate in Parliament.