Why does the British tax year start 4th April?
Prior to the eighteenth century, the calendar year began on 25th
March and so it was quite natural for the tax year to start on the
same date. When the calendar was reformed the Inland Revenue
decided not to confuse the populace further by changing the dates
of the tax year as well. The Gregorian calendar was adopted in
Britain some time after it had been instituted in Europe, and in
order to correct the time lag which had built up, it was decreed
that September 2nd, 1752 would be followed by September 14th. This
move was unpopular with the general public who took to the streets
in fury, shouting that they had been robbed of 11 days of their
lives. In such a climate the Inland Revenue felt that they could
not start the next tax year on 25th March as usual, as the already
irate taxpayers would effectively be paying a full year's tax for
only 354 days. The solution was to move the start of the following
tax year back to April 6th, where it has remained ever since.