As a rule, interchangeable license plates are license plates shared between two vehicles. They are ideal for people who own two cars, but do not use them at the same time. As you are only permitted to drive the vehicle to which the license plates are attached.
Interchangeable plates can help you save on your insurance premiums. You will also save costs with the Driver and Vehicle Licensing Office and when paying your vehicle tax. If you have taken out partial casco cover, this also applies to the vehicle that is parked without a license plate. The rules around interchangeable license plates differ by canton. You can find out more information from your local DVLO.