I have a client who is not in SA (he has a UTR for legacy reasons) but wishes to claim legitimate mileage expenses of £5000 for the tax year 2019/20.
He has shown me a copy of two P800 calculations (2018/19, 2019/20, both dated 11 Aug 2020) that he was sent. His 2018/19 calculation had an overpayment of £1000, but was carried forward to the 2019/20 tax year. His 2019/20 calculation had an underpayment of £500, but due to the overpayment from the carried forward 2018/19 year, he was still sent a cheque of £500 which he banked.
The problem is that when I input his 2019/20 earnings into my software, I obviously have an underpayment of £500, and therefore even when I add in the mileage, the refund is £500 less than what it should be. There is no way for me to tell the 2019/20 tax return that there is an overpayment from a previous tax year that was never fully sent but was used to offset the tax owed in 2019/20.
(There is a field for the opposite scenario, where there is an underpayment carried forward, but not for an overpayment.)
As you cant claim expenses over £2500 via PAYE, what can my client do to claim this tax back without suffering extra tax as a result of the SA system not understanding that there was already an overpayment offset against it from 2018/19?