Overpayment repayment

Hi, If you’ve been overpaid an allowance for approx 5yrs what is the correct way to repay this?

Hi,
Please contact HMRC by webchat or phone via:.
Income Tax: general enquiries
We can remove the allowance for all years affected, calculate the amount due, and advise you on your repayment options, depending on the underpayment calculated.
Thankyou.

Thanks but not sure I made my question clear enough I may have been given an extra sum of money in allowance for in my pay check (I’m PAYE). This was tax deductible and from my employer. It was over a 5yr period. If they say they want me pay it back do I pay back the net overpayment and they can cla the tax back via HMRC? If it is net i owe them is this deducted from my pay check over an agreed period of time? You mention underpayment, what would that relate to?

Hi 
In this instance please contact HMRC and request to speak to a Technician Income Tax: general enquiries who will be best placed to look into and advise on the complexities of your individual circumstances.