“It’s a scandal that could well grow with potential issues around underpayments to divorced women also highlighted.”
Ms Morrissey believes the mistakes made by the DWP could prove expensive, as it looks to ensure these problems do not continue to occur.
She said: “The DWP faces a costly exercise to correct these errors and will need to look at how IT systems and processes can be overhauled to prevent this from happening again.
“However, it also needs a fundamental review of how it communicates with people who come to them with concerns and the information it issues on a benefit that forms the very backbone of many people’s retirement planning.”
Tom Selby, head of retirement policy at AJ Bell, added: “It is scandalous so many pensioners, mainly women and some of whom will have been struggling to make ends meet, suffered as a result of the DWP’s stone age administration processes.