when does tax year start
HM Customs and Revenue self assessment notice to complete a Tax Return (Picture: Getty) Although some parts of the world choose New Yearâs Day to be the start of their tax year, the UK starts theirs in April. A UK tax year runs from 6 April to the following 5 April â so anyone who is required to file a tax return will shortly be receiving a notice advising them to do this for the year thatâs just ended.