Benefits claimants have been underpaid £2.6billion by the Department for Work and Pensions (DWP) - so check to see if you are owed something.
Recent figures from the DWP show that it underpaid 1.2% of benefits in the year to April 2022.
But while some claimants got too little in benefits, some had the opposite issue.
DWP also overpaid benefits by £8.6billion in the period - the highest rate ever.
Underpayments and overpayments happen due to mistakes by DWP, councils, HMRC, fraud and claimants making errors.
Have you been underpaid by the DWP? Let us know: mirror.money.saving@mirror.co.uk
Which benefits were underpaid?
DWP underpaid £410million in Universal Credit in the period, but overpaid £5.9billion.
It underpaid state pensioners £540million, but also overpaid £110million.
Housing Benefit was overpaid by £950million, but underpaid by £210million.
Pension Credit was overpaid by £350million, but there were £100million of underpayments too.
What happens if you are underpaid benefits
Normally, DWP will spot the problem and pay you what you are owed as a lump sum.
But if you think you have been underpaid and the DWP has not contacted you or corrected the issue, you can contact them to enquire.
For example, Universal Credit claimants can call a helpline on 0800 328 5644 or use their online account.
If you think you have not had the correct state pension amount, you should contact the Pensions Service arm of the DWP directly.
You can call on 0800 731 0469, but be aware that the lines are only open from 9.30am to 3.30pm Monday to Friday.
What happens if you are overpaid benefits
If you have been overpaid benefits, the DWP can recover any extra from you.
If the Department for Work and Pensions (DWP) has paid you too much Universal Credit, it will take back the money from your future payments.
Normally this is in the region of a 15% to 25% reduction each month.
You can ask if they'll let you not pay back the overpayment - but they don't need to say yes.
This is called "exercising their discretion not to recover an overpayment" and is down to the discretion of the DWP.
DWP has been approached for comment.
Earlier this year The Mirror reported that thousands of Brits could be due a payout from the DWP after being underpaid housing benefit.
Those who are affected did not get the maximum amount of housing benefit they were entitled to.
The mistake is because of a separate issue relating to underpayment of Employment Support Allowance (ESA) which happened when some claimants were moved over from older benefits.
This could include those who moved to ESA from Incapacity Benefit, Severe Disability Allowance or Income Support from 2011 onwards.
ESA is a benefit designed to help those who are ill or disabled and is worth up to £74.70 a week.
