If you buy a used vehicle with number plates, you as the new owner must change the owner of the vehicle in the Register of Motor Vehicles within 4 weekdays from the time of purchase.
If you buy a used vehicle that has been deregistered in the Register of Motor Vehicles, you must register it again within 4 weekdays.
If you sell a used vehicle, you should note that the new owner is required to change the owner of the vehicle in the Register of Motor Vehicles within 4 weekdays. If this is not done, you can ask the Danish Motor Vehicle Agency to deregister the vehicle.