If you intend to repair your car or another vehicle abroad, you are liable for VAT on the service.
If you yourself travel with the vehicle, the value limit for travellers apply. The limit is NOK 3,000 or 6,000 depending on how long you have been outside of the country. If the value of the repair/service exceeds the limit, you must pay 25 per cent VAT on the entire cost and eventual freight costs.
More on temporary export and import in connection with repairs
Norwegian Customs does not require that you register the vehicle as temporarily exported when driving it out of the country yourself, or when transporting a Norwegian registered vehicle on a trailer (with licence plates affixed). You should nevertheless enquire with the customs authorities in the country in which you intend to carry out the repair/service whether you need a temporary export declaration from Norway. If this is the case, you must visit a local customs office in Norway who will issue this at no cost. If you are transporting an unregistered (previously Norwegian-registered) vehicle on a trailer, you must have an export declaration.
You must also ask the customs authorities in the country in which you intend to carry out the repair/service, which procedures you should follow when crossing the Norwegian border. It may for example be the case that you are required to provide a deposit for VAT based on the value of the vehicle.
When reimporting the vehicle, you must enquire with the customs authorities in the country in which the vehicle has undergone repairs/service on which procedures you must follow upon re-export from there.
Upon reimport to Norway you are not subject to VAT if the repair/service costs are below the value limit for travellers.
If the repair/service costs exceed the value limit, you are obliged to stop in the red zone for customs clearance. You must pay 25% VAT on the entire amount, including any transport costs.
If you are using a professional shipping agent to transport your vehicle, it will be aware of the customs procedures.
Any refunds/repayment of foreign taxes (e.g. VAT), must be arranged directly with the garage. Norwegian Customs cannot assist you with this.