IS IT MANDATORY TO REGISTER YOUR CAR IN PORTUGAL?
If you opt for RNH status, you become de facto resident in Portugal. You are then obliged to take the necessary steps to register your vehicle with the competent Portuguese authorities, and possibly pay import taxes. However, under certain conditions, you will be entitled to an exemption from vehicle tax (ISV).
As a non-resident, your vehicle must be registered and insured in your country of origin. Your vehicle cannot drive in Portugal for more than 6 months and your insurance may not accept more than 3 consecutive months of absence from its country of origin.
WHAT ARE THE RISKS?
If you decide to drive without registering your car in Portugal you will incur more or less heavy fines and the obligation to comply with the ISV, knowing that your date of arrival in Portugal will be the basis of calculation.
For insurance companies, in the event of an accident, they will always hide behind the most favourable sections of the law. You cannot have a secondary residence in Portugal and drive a car registered in another country.