A study has found that less than half of cars that claim to be able to accommodate three child car seats in them actually can.

It was not just five-seat cars that couldn’t carry the seats, either, as even some seven-seat vehicles that consumer publication What Car? tested couldn’t handle three child seats.

Just one-in-eight SUVs that were tested could fit three child seats in at once, while MPVs proved the best performer with two thirds of vehicles being able to fit three child seats in.

Sixteen different cars were tested, each using the same three children, aged seven, four and 11 months, and the same three child seats.

The best performing cars were the Audi Q7, Vauxhall Zafira Tourer, Citroen Grand C4 Picasso and Volkswagen Touran, which could all fit three child seats in across a single row.

While several of the cars tested, including the BMW X5, Seat Alhambra and Volvo XC90, could still fit three child seats in, they had to be placed across two rows to fit safely.

Disappointingly, though, several large practical family cars could only fit two child car seats, even when several of the vehicles have seven seats. These cars include the Renault Grand Scenic, Ford S-Max, Peugeot 5008, Skoda Kodiaq and Nissan X-Trail.

What Car? consumer editor Claire Evans, said: “Size doesn’t always equal practicality – even some of the biggest SUVs can only accommodate two child seats.

“Our research only shows one possible scenario in terms of the combination of child ages and car seat styles, but it highlights the need for parents to check that their child seats will fit properly into a car before buying it.”

All children, until they are 12 years old or 135cm tall, must use car seats by law. This means that car seats change considerably in size depending on who they are being used for.