Car seat law UK checker

A child must travel in a child car seat until turning 12 years old or growing to 135 cm, whichever happens first (GOV.UK). The regulations call such a passenger a small child: someone under 12 years and under 135 cm tall. Reaching either limit ends the duty. A child of 9 who already measures 135 cm can move to the adult seat belt, and so can a shorter child who has turned 12 years old. Weight is not a legal threshold; it only decides which seat suits the child. The duty applies in the front and in the back. It comes from the Motor Vehicles (Wearing of Seat Belts) Regulations 1993 for rear seats and a sister set of regulations for front seats, made the same year. Driver responsibility is personal: whoever is at the wheel answers for every passenger under 14 years.

At 6 and 115 cm, the checker's default, the verdict is "Child car seat required" with 20 cm still to grow. At 11 and 134 cm only 1 cm remains, and at 9 and 135 cm the adult belt is enough. The sources for these cases are under checked cases.

The large line at the top is the verdict, and the rows below it explain how it was reached.

• The front seat row judges that seat for this child, seat direction and airbag setting, even when the rear was chosen.
• The age and height rows repeat both limits, and "Still to grow" shows how far height alone is from ending the duty.
• The weight group is the R44 class that matches the weight entered, as printed on the orange label of older seats.
• The last rows give the £100 fixed penalty, the £500 court maximum and the penalty points, which are 0 in Great Britain.

Yes, at any age: the law sets no minimum age for the front passenger seat. A small child there needs the same child seat as in the back.

The one outright ban concerns airbags. A rear-facing seat must not be used in front of an active front airbag (Road Traffic Act 1988, s15). The Highway Code repeats the rule (Highway Code rule 101). For a baby in a rear-facing seat in front with the airbag on, the checker shows "Not allowed: front airbag is on". With the airbag switched off, the front seat row reads "Allowed".

Only EU-approved child seats can be used in the UK, marked by a label with a capital E in a circle (GOV.UK). Two approval schemes exist, and the label says which measure a seat follows.

• A height-based seat is approved under R129, known as i-Size, and keeps a child rear-facing until older than 15 months.
• A weight-based seat follows ECE R44, version 04, whose overlapping groups end at 13 kg (0+), 18 kg (1), 25 kg (2) and 36 kg (3).
• ISOFIX anchor points, built into the car, let many seats of either scheme click in without the adult belt.
• A high-backed booster seat lifts the child and guides the belt past a backrest and side wings; a booster cushion is the backless pad.

Weight-based seats are no longer sold new, but using an approved one that fits the child stays legal.

The exceptions sit in regulation 10 of the rear seat regulations, so they cover the back of the car only. Most start at the age of 3 years (GOV.UK).

• Taxi or minicab, meaning any private hire vehicle, with no child seat on board. A child of 4 gets "Adult belt allowed by exception", since that route opens at 3 years. A younger child may ride with no seat or belt: "No child seat or belt required".
• Unexpected necessity over a short distance, a phrase the law leaves undefined. From 3 years the belt will do; below that age there is no exception, so a child of 2 still needs a seat.
• No room for a third child seat, because two occupied ones fill the back. From 3 years a child may then wear the belt; a younger child moves to the front in a child seat.
• No seat belts at all, as in some classic cars: from 3 years a child may ride in the back unrestrained. A younger child may not travel, and a small child may not sit in front.
• Large buses and coaches are exempt, and a minibus follows rules of its own. Police and emergency vehicles are exempt too, as is a taxi with a fixed partition.

A doctor can issue an exemption certificate when a child cannot use a restraint or seat belt because of a medical condition (GOV.UK). This medical certificate is what lifts the duty. With it, the checker returns "Exempt with medical certificate".

A child with a disability may instead use a disabled person's belt, or a restraint designed for that child's needs (regulation 10). That route needs no certificate.

Breaking the rule can bring a fixed penalty notice of £100, or up to £500 if the case goes to court (GOV.UK). The driver answers for every passenger under 14 years; older passengers answer for themselves.

No penalty points are added to a licence in Great Britain. The Department for Transport consulted on adding them. The consultation closed on 11 May 2026 with no outcome published, so the law has not changed.

Northern Ireland is the exception within car seat law UK-wide: its fixed penalty is £60, with 3 points. The checker models Great Britain only.

An approved seat of the right size can still be fitted unlawfully, and GOV.UK names the main cases.

• A child seat needs an adult belt with a diagonal strap, unless it is made for a lap belt or fixed with ISOFIX.
• No child seat may go in a side-facing seat, found in some people carriers and vans.
• No rule bans a second-hand car seat, provided it carries an approval label and suits the child. Its crash history does not show on that label.
• How these rules become the checker's verdicts is set out in the methodology.