Women receiving a pension of as little as £1 a week could be owed sums equivalent to lottery wins, according to a former pensions minister.
As many as 5,000 women could be owed thousands of pounds in backdated payments, said Sir Steve Webb, who is now a partner at consultants LCP (Lane Clark & Peacock).
Sir Steve estimated the total bill to be a quarter of a billion pounds if all those eligible made claims, but warned some could be missed by data searches currently being carried out by the Department for Work and Pensions (DWP).
Women he’s helped recently included one who was entitled to £56,000 in back pension, another to £33,000, and a third to more than £60,000.
Some women were until recently on pensions of only around £1 per week, he said – and under a little-known rule are allowed to claim back pension to before a 2008 rule change that prevented many married women from doing so.
The women who qualify for this special concession are those with no basic pension, but who are now receiving a tiny amount of graduated retirement benefit (GRB).
Three main elements made up the old state pension system:
• A basic state pension
• An earnings-related pension
• An older GRB, which ran from 1961 to 1975
The eligible women can now make a backdated claim back to when their husband turned 65, Sir Steve said.
Among those to have benefited is Carole Davies, whose husband retired in 2005.
"After four months of looking for answers from the DWP we enlisted the help of Sir Steve and, to my amazement, the DWP have now confirmed all my due monies will come to me," she said.
"I would advise all women in my position to seek advice and push hard for everything they are due as it is their right."
In March, documents revealed in the chancellor’s budget showed thousands of women who were underpaid the state pension were in line for top-ups, with the bill put at around £3bn.
But Sir Steve said the group of 5,000 women were likely to be missed by the DWP’s data search – and they should contact the department as soon as possible to see if they were owed money.
He said: "It is incredible that there are thousands of women getting such tiny pensions, but even more incredible that many could potentially be entitled to tens of thousands in back payments.
"It is as if they are sitting on unclaimed winning lottery tickets.
"It is very important that women on these very small pensions make contact with the DWP as soon as possible to see if they could be entitled to a windfall."
A DWP spokesman said: "The action we are taking now will correct the historical underpayments that have been made by successive governments and anyone impacted will be contacted by us to ensure they receive all that they are owed."