So that probably sounds like a daft question to some, but bear with us.
The language of private number plates can be a bit confusing to the uninitiated. Number plates enthusiasts and we, the dealers, probably don't help. Even though the registration number assigned to your car and the (usually) plastic number plates that display it are two very different things, we often use terms that blur the distinction.
Registration nearly always refers to the actual number that identifies your car in DVLA's records, and which is displayed on your plastic number plates. There, that bit is nice and straightforward! However, the term "number plate" or variants such as "private number plate", "personal number plate" can mean the registration number, the plastic number plate or both.
If someone says “I'm going to get private plates for my car”, then they really mean that they're going to purchase a private registration number and have it transferred onto their car to replace the number that is currently assigned. Of course, they'll need to buy the physical, plastic plates too, in order to display that new registration.
As the plates are the tangible result of the purchase, it's not surprising that the language we use focuses on that - on the visible, touchable item that shows we got something for our money.
The two things, the registration itself and the plates that display it, are distinct from each other and they each have different rules and regulations that must be observed.
When your car is first registered, the registration it is given is an identification code that does several things.
The two-letter regional identifier called the Local Memory Tag shows approximately where, geographically, the car was registered.
Date of first registration
It shows the date that the car was first registered. For practical purposes this defines the official age of the car.
It provides you, and the authorities, a way of identifying your car and telling it apart from all the others
For more details on the character codes used to show this information, please see how formats work.
When you buy a private registration and change your number plates, the last two of the things in the list above may no longer be shown by your plates. While you may, of course, purchase a number that bears the same date and location codes as the original number, this is vanishingly rare.
People usually buy registrations that are quite different - often with the intention to hide the age of their cars. While the car registrations regulations don't allow you to make a car look newer by showing a more recent date code, there is no ban on hiding the car's age altogether buy assigning a number in a format that has no year code.