You’re looking for the 3rd and 4th character in the registration plate to tell when the car was registered. A car with registration AB70 CDE was registered between 1st September 2020 and 28th of February 2021.
Registered datePlate 1st March – 31st Aug 201919 1st Sept – 28th Feb 202069 1st March – 31st Aug 202020 1st Sept – 28th Feb 202170 1st March – 31st Aug 202121