What Car? Q&A - Why are there two numberplates each year
A: Since the numberplate system was revised in 2001, there have been two changes of plate each year - one on March 1 and the other on September 1.
That means that a car registered in 2007, say, could have three different 'plates'. If it was registered between September 1, 2006 and March 1, 2007 it would carry a '56-plate' - meaning the first and second numbers on the plate would be '5' and '6'.
If it was registered from March 1 to August 31, 2007 it would be an '07-plate' or, if registered between September 1 2007 and February 31, 2008, a '57-plate'.
Before 2001, numberplates were prefixed with a single letter, but because there are a limited number of letters in the alphabet, a new system was needed.
The current system is set to be in operation until 2049, so you needn't worry about further changes for a while.