If you have just bought a new vehicle or just acquired a secondhand one and do not intend to use it immediately, you will have 21 days from the date of purchase (as specified in the registration document or the notification of transfer of vehicle ownership) to furnish a declaration of non-use. In that case, the declaration will commence from the first day of the month in which the sale takes place, or the first day of the month of registration in the case of new vehicles.
Make sure you notify the seller that you are intending to declare the vehicle off the road and that you need him or her to ensure that the change of ownership is notified to the National Vehicle and Driver File as soon as possible.