I received a cheque from HMRC through the post on Christmas Eve with a cheque for over £500 and saying i had paid too much tax. Today I have received 2 letters from HMRC, one regarding my tax calculation for 2017-2018 and the other containing my tax calculations for 2018-2019 and also 2019-2020. The 2017-2018 one says I owe £715 which must be paid by March 23rd. The 2018-2019 says they owe me £514 (underneath says the amount HMRC owes you will be carried forward to a later year) and the 2019-2020 one also says they owe me £514.
So.. I have paid the cheque in that they sent, but do I now owe them that back as well as £715??? In 2018 I was told I had paid too little tax in 2017-2018 (due to employer putting wrong tax code and I did not pay anything for a few months) which I then started paying back slowly, as I couldn't afford it all in one go, so my tax code was changed so I was paying more.
Really confused and irritated by this, so any advice would be good