Martin Lewis has urged people to make a claim as around 100,000 are entitled to up to £6,000.
Speaking on his ITV Martin Lewis Money Show Live on Tuesday evening the consumer champion urged people to act now. He said: "Make sure you look this up if it smells like it is relevant to you or someone you know. There are hundreds of thousands due an average of £6,000 back in underpaid state pensions because of a former DWP error."
Martin added: "Married women and widows may have been underpaid. It's complicated."
