I processed a P45 for a leaver who left on 31/03 with that as his leaver date. I then paid him his final pay in week 1. I have been advised to change the tax code to 0T week 1 and make a payment after leaving. Because of the change in tax code when I refund/correct the pay made in week 1 and re pay with the new code it leaves the pay as a negative net amount and Sage will not process a negative payment. I'm at a loss as to what to do really and can never get through to HMRC.