More than a million people have been told they must repay benefits they have been paid incorrectly. According to The Big Issue there are about 1.1 million people who owe money to the Department of Work and Pensions (DWP)

But many of these only find out they are not entitled to the money long after it has been spent. They then must find ways of paying back the cash - even if the mistake is not theirs but made by the DWP. There are several issues that can lead to overpayment, some mistakes by the claimant and others as a result of DWP errors or delays.

There are several types of errors that can result in overpayment, some attributable to the claimant, others to the DWP.

Technical issues

Occasionally, mistakes made by the DWP or HMRC result in people receiving excess funds. In such cases, you will be required to repay any amount you're not entitled to, reports the Mirror.

This could involve receiving duplicate payments by error or being allocated an incorrect sum due to delays in processing or updating your details. Regardless of who is at fault, any overpaid amount will need to be returned.

If the benefit in question is Universal Credit, Jobseeker's Allowance, or Employment and Support Allowance, it's likely that any overpayment will be reclaimed. However, certain other benefit overpayments resulting from a DWP mistake might be waived.

Failure to report changes in circumstances

Under government regulations, you will be obliged to repay funds if you failed to promptly report a change in circumstances. This could apply if you relocated or ceased to receive a benefit that qualified you for the funds.

Human error

One issue arises when you've provided inaccurate information. If you declared the wrong income amount for yourself or your partner, it can affect your entitlement.

Should this occur, the DWP may demand repayment. There's no cap on the repayment amount or time limit for claims.

Supplying false details

If you obtained the payment after providing incorrect information during your application, you'll need to return the funds. This might include errors such as entering the wrong date of birth on your form.

Advances or interim payments

Certain people can receive advance payments on their benefits, for instance whilst awaiting their complete application to be processed. Nevertheless, when the full claim is settled, this sum will be treated as an overpayment requiring repayment.

Hardship payments may also require repayment. These are designed to assist those facing benefit sanctions but typically must be returned once sanctions conclude.

Following a claimant's death

Failing to promptly inform the DWP can occasionally result in payments continuing after someone's passing. These "direct payments after death" are normally recovered through the deceased person's bank account.

Child benefit

Child Benefit can also be overpaid in certain circumstances - for instance, if one partner's earnings exceed £60,000, some funds may need returning. Should income surpass £80,000, full repayment becomes necessary - though these are generally handled via taxation.

Additional payments

If you have been overpaid from funds including Maternity Payment or Winter Fuel Payment due to a government error, they cannot reclaim the money. However, if the mistake lies with the claimant, it can be reclaimed.

The government has outlined methods to dispute a decision if you believe it has been made in error. It states:

• Ask for mandatory reconsideration - ask for the benefits decision to be looked at again (mandatory reconsideration) You normally need to do this within one month of the date on your decision letter
• Appeal the decision to a tribunal -if you're unhappy with the decision after mandatory reconsideration, you can appeal it to a tribunal
• Ask for the tribunal's decision to be 'set aside' (cancelled) - if you disagree with the decision, you can ask for it to be set aside (cancelled). The decision letter from the tribunal will tell you how to do this
• Appeal the tribunal's decision -if you think the decision was wrong for a legal reason, you can appeal to the Upper Tribunal
• Check if you can get legal aid -you may be eligible for legal aid to help you appeal to the Upper Tribunal. Check if you can get legal aid

The government suggests several ways to determine if you are entitled to additional funds that you are not currently claiming. It recommends: "You can use an independent, free and anonymous benefits calculator to check what you could be entitled to."

This will provide an estimate of:

• the benefits you could get
• how much your benefit payments could be
• how your benefits will be affected if you start work or increase your hours
• how your benefits will be affected if your circumstances change - for example, if you have a child or move in with your partner

For other information on income-related benefits, contribution-based benefits, Universal Credit, Council Tax Reduction and Carer's Allowance use:

• entitledto benefits calculator
• Turn2us benefits calculator
• Policy in Practice better off calculator

You can also check with a local benefits adviser to find out what you could be entitled to. However you cannot use the calculators if you are under 18. They will not give accurate results if you're a prisoner, student, not a British or Irish citizen, on strike, living outside the UK or living permanently in residential care or a nursing home.