Car tax registration UK — your vehicle's registration number reveals important information about its age and registration date, which directly affects which VED rates apply.
Understanding the Age Identifier System
UK vehicle registration numbers since 2001 use a two-letter age identifier that changes every 6 months. The first letter identifies the half-year (March-August or September-February), and the second letter identifies the year. A vehicle registered in March 2025 has the identifier "25"; registered in September 2025 has "75".
How Registration Date Affects VED
Vehicles registered from April 2025 fall under the current graduated first-year VED system with 20 bands. Vehicles registered before this date may have been taxed under previous VED structures. However, the standard annual rate of £190/year for petrol/diesel applies from year 2 onwards regardless of registration date.
New Registration Numbers and Road Tax
A new registration number can be assigned to a vehicle without affecting its VED. The road tax rate is based on the vehicle's CO2 emissions and first registration date — not the specific number on the plate. Adding a private plate or a new registration number does not change your road tax band.
Regional Registration Prefixes
Pre-2001 registration numbers carried regional memory — A for London, B for Birmingham, etc. These regional prefixes have no effect on road tax. The current single-number age identifier system replaced regional prefixes in 2001 for new registrations.
Conclusion
Car tax registration UK: the age identifier shows when a vehicle was first registered, which determines first-year vs standard VED rates. Registration numbers do not affect road tax. GOV.UK has full registration guidance.