Licence (registration sticker) expired on ...
A vehicle must have a licence to legally be driven on the road. Licenses can be purchased for a period of 3 to 12 months.
When this period passes, the licence has expired and must be renewed if the vehicle is to be used on a public road.
Most vehicles need to be continuously licensed (there are some exceptions). This means that if the licence expired say 2 months ago, this 2 month period must still be paid for. You cannot save licensing fees by delaying your licence renewal.
The current owner (vehicle seller) is responsible for paying all licence fees that are due up until the date that a Change of Ownership officially takes place. The new owner (vehicle buyer) is only responsible for licence fees incurred after the Change of Ownership takes place.
Note: vehicles must have a valid WOF or COF to be re-licensed.