Thousands of workers on low incomes will be getting letters from HMRC making them aware they are entitled to extra pension top-up cash but there are fears many will not claim the money they are owed.

Since 2016, HMRC has agreed 25,000 settlements with employers and individuals over their use of loan schemes, which will raise around £4.2bn in revenue. However, over 40,000 people and 5,000 ...