After nine months trying get my pay sorted out (previously underpaid) I have now been over paid nearly £3,000 due to being paid at wrong increment (which has been backdated). I intend to bank to extra an earn some interest on it until they want it. The problem I have is that I have been taxed etc on the overpayment and therefore can not put all of the money to one side. What happens when they want there money back as I will have only seen about £2,300 of this money as the tax/NI man has seen the rest. The questions are 1) I think they will want the entire amount (inc tax/NI paid) is this correct. 2) Can I get the extra tax I have paid back in year, or do I have to wait until the end of the tax year. 3) How do get the rebate for the extra NI stamp that I have paid. Lastly all this is as a result of JPA cocking my pay on promotion and change of CEQ last year, I and the pay staff at my unit have raised a number of calls with JPA and they have still not got it right. How can I escalate this with someone other than a JPA monkey reading a script. Any pay/JPA gurus out there?