I,Q and Z explained

It is only with the advent of new style numberplates that Z has appeared as a valid numberplate character. Z and I have previously appeared on Irish numberplates and Q on "kit cars".

The reason I Q and Z are generally omitted from the UK numberplate system is because they can be easily read as 1 0 or 2 - something which would hinder the authorities in identifying a vehicle or enforcing say the Congestion charge.

Q numberplates in particular are excluded from the cherished transfer scheme and Q registrations are issued to vehicles where the numberplate has been made void.

I,Q and Z are not used as they look similar to 1, 0 and 2 respectively.
Exceptions-

* CURRENT STYLE AB51ABC numberplates use Z
* IRISH PLATES use I and Z
* Q Plates with Q as the prefix i.e. Q123FDD are reserved for kit cars and vehicles with undetermined age- these vehicles cannot participate in the transfer scheme at the time of writing.