Today I received a P800 calculation from HMRC telling me I owe them £1 ,340 underpaid tax from 2015-16.
However, the calculation includes an £889 underpayment from 2014-15 wh ich I am currently paying back via a reduced tax code - it will be fully re paid by the end of this tax year.
Is the P800 calculation wrong or is this how they work? Collect it once, t hen collect it again and hope I don't notice?
Should I contact them?