Licence (registration sticker) will expire on ...

This is an advisory message simply telling you that this vehicle's licence will expire in the near future.

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.

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.