About AT53 LAT
Current style
AT53 LAT is a current-style registration, the format the DVLA has issued since September 2001. The first two letters, AT, are the memory tag, and A is the region letter for Anglia.
The number 53 is the age identifier for September 2003, so this plate can go on any vehicle first registered on or after 1 September 2003. A registration can never make a vehicle look newer than it is, so it cannot go on anything older.
Private registrations move between owners through the DVLA: once a price is agreed, the registration can go straight onto your vehicle, or be held on a retention certificate until you are ready to use it.