Using seat-belts / safety belts when driving in Portugal
In Portugal, all in the vehicle must use seat-belts. Special laws for children apply – per EU standards. Car rental company will advise.
Driving with children
Children under 12 years of age and less than 135 cm in height: Must use an approved 'restraint system' suitable for their height and weight. Using seat belts alone is not sufficient. They must be secured in the back seat of the vehicle, except if the child is less than 3 years old. In that case 1) the child may occupy a front (passenger) seat in the vehicle equipped with a special child safety seat that faces towards the rear of the vehicle, 2) the safety airbag must be disabled for that vehicle front seat.
Children with recognised disabilities may use seat or other restraint systems suitable for their specific needs, provided these are prescribed by a specialist.
The law may allow some vehicles not to have seatbelts for all passengers. For example, large passenger transport vehicles such as buses. Children under 3 years old may never be passengers in any vehicle without seat-belts. Other children may use these vehicles, but never in a front seat. Realistically this provision may not be enforced strictly. For example an adult with an infant child is not going to be denied use of a bus which is part of a public transport system.
The fine for violating seat belt restrictions is €120-€600 for each person transported improperly.
The law regarding the use of seat-belts and other restraining systems in Portugal closely follows EU standards. If you rent a vehicle, the rental company should know the law and offer to provide you with any additional equipment you need. If you are transporting children under the age of 12, any good retailer selling vehicle safety equipment can advise on special car seats. Disabling the airbag on a front passenger seat (to install and use an infant restraint seat) may be difficult. Check with the vehicle manufacturer. The police will expect you to have done that.