https://www.bbc.co.uk/programmes/articles/396WFxWxwPljdrgJS2gXYzs/home-responsibilities-protection
This is a really useful link, HMRC have set aside the money, but their records are missing the NI details of many of those who are owed higher state pensions and backdated payments too in some cases. There are of course a few dodgy companies opening up who will offer to do this for you, with litigation that is neither necessary nor appropriate. Someone told me about one this weekend, the company sounds very suspect, and I don't know its name because I knew I didn't need their services. Needless to say someone who is not legally trained is using AI to write legally worded letters in order to make the claims for people, where as the links contained in above take 15 mins ish, just have your NI number handy. Anyone offering to do this for you will be asking for a fee or a commission - this company apparently has their eye on millions ..... of your money.