What is the Tax Year in the UK?
A tax year starts on 6 April and runs to 5 April. All the tax rates and allowances you see relate to a single tax year and most change on 6th April at the start of each new tax year.
Why Does the Tax Year Start on 6 April?
The reason each tax year starts on 6 April dates back to medieval times! Back in the 1500s, the UK used what was known as the Julian Calendar (named after Julius Caesar).
In the Julian Calendar the New Year started on 25 March, suspected to match the spring season, but more importantly, it differed from the solar calendar by 11.5 minutes.
In order to iron out this difference, towards the end of the 1500s Europe changed to the Gregorian Calendar but the UK continued using the Julian Calendar.
By the 1700s the UK was 11 days out of alignment with the rest of Europe. To fix the problem in 1752 11 days was simply cut out of the year!
But the government didn’t want to lose out on taxes. So they added 11 days to the end of the year and the tax year restarted on 6 April.