Universal Credit claimants face waiting another year for the Department for Work and Pensions (DWP) to fix an internal system that should have automatically updated their state pension records.
A recent investigation by This is Money revealed that people on Universal Credit were only having their state pension records manually corrected as they reach state pension age.
Lost National Insurance credits can mean people could get less state pension when they retire or they could waste money buying top-ups they don't need.
At the beginning of February, Liberal Democrats MP Wendy Chamberlain asked for answers on Universal Credit and state pension records in Parliament.
A letter to Chamberlain from Employment Minister Guy Opperman has since confirmed the flaw in the system.
The letter revealed that the automated process to add Universal Credit claimants' data to their state pension records was suspended in 2017/18.
The employment minister also said corrections would not be completed until next April.
In the letter, he wrote: "The vast majority of people affected are many years away from reaching state pension age and will not be impacted by this issue when they make a state pension claim.
"For those who do need to claim their state pension, HMRC and DWP have implemented a manual process to correct NI records and state pensions.
"For those already claiming their state pension, who are affected by this issue, their state pension will be re-assessed and any underpayment issued accordingly as part of normal processes."
Over the course of the investigation, it was claimed the issue was "internally well-known".
This is Money approached the DWP multiple times with cases of missed National Insurance credits.
Additionally, the Gov.uk website still claims Universal Credit claimants have their National Insurance credits updated automatically.
In response to a recent approach which featured 10 cases, a DWP spokesperson: "All of the cases raised have now been resolved and we are sorry for any inconvenience caused.
"We are working with HMRC on an improved process to add historic and future Universal Credit National Insurance credits to National Insurance records."
Former Pensions Minister Steve Webb told This is Money that the whole thing was a "shambles".
He said: "Yet DWP has made no effort to tell the public what was going on behind the scenes, and in particular to make sure that people do not risk wasting their money paying voluntary NICs for years which should be covered by credits.
"DWP admit in their letter that there are people in retirement who are being underpaid which shows that the current manual processes are not working reliably.
"There needs to be a change of culture at DWP where they are transparent when things go wrong rather than trying to fob people off with excuses."
At the start of the year, nearly 5.9million people claimed Universal Credit and This is Money believes more could possibly be affected once you take into account those who no longer claim.
The Mirror has approached the DWP for comment.
