Before going any further, it is important to note that there are many different car seat sizes and types in Spain according to height and weight. It is Spanish law that no child under 1.35 meters, (roughly 5 feet), is without a car seat or booster seat of some kind.

Yes, in 2026, Spanish law is very strict regarding child safety. Children under 1.35 meters (approx. 4'5") in height must use an approved child restraint system (car seat or booster) and must travel in the rear seat of the vehicle. The only exceptions for using the front seat are if the car has no rear seats or if the back seats are already occupied by other children in car seats. For taxis, the rules vary slightly: within urban areas (city limits), you are technically not required to use a car seat, but for any journey on a highway or "interurban" road (such as a trip from the airport to your hotel), a car seat is legally mandatory. In 2026, most reputable taxi apps in Spain like Cabify or FreeNow allow you to book a "Kids" category vehicle equipped with a seat. For rental cars, you must always pre-book a seat, as failing to use one can result in a fine of over €200 and is considered a serious safety offense.