Rear facing child car seat law

For an R129 height-based seat the answer is until the child is over 15 months old. GOV.UK uses those words. At 15 months the seat still faces the rear. After that birthday-month, a forward facing child car seat is permitted if the label covers the child's height and any maximum weight.

R44 group 0 (0 kg to 10 kg) and group 0+ (0 kg to 13 kg) are rear facing baby carriers or baby seats with a harness. Group 1 starts at 9 kg and may be rear or forward facing. A child who has reached 9 kg can legally use a suitable forward facing R44 group 1 seat even if they are not yet over 15 months. That option exists only on the R44 system. It does not let you rotate an R129 seat early.

nidirect describes the first i-Size stage as birth to 15 months, rear facing, for a length of about 83 cm. It also says it is possible to keep a child rear facing beyond 15 months, up to 105 cm, depending on the product. Forward facing R129 seats can be used from 15 months on a seat that allows it, but the label is still the limit.

Only if the frontal airbag is deactivated and both the seat and the vehicle instructions allow that position. GOV.UK requires the front airbag to be deactivated before a rear facing baby seat is fitted in the front passenger seat. Highway Code rule 101 is stronger still: a rear facing baby seat must not be fitted into a seat protected by an active frontal airbag, as in a crash it can cause serious injury or death.

If the airbag cannot be switched off, that front seat is not available for a rear facing baby seat. Use a rear seat the handbook permits. Some cars hide the airbag switch in the glovebox, some need a garage to disable it, and some passenger airbags cannot be disabled at all.

Reactivate the airbag when the rear facing seat comes out. An adult or a forward facing older child in that seat may need the airbag live. Follow the vehicle handbook, not a forum post.

A rear facing seat can use ISOFIX, a support leg, a vehicle belt, or a combination the manufacturer specifies. GOV.UK says you must only use a child car seat if the car's seat belt has a diagonal strap, unless the seat is designed for a lap belt or is fitted using ISOFIX.

Never fit a child car seat on a side facing seat. Never thread the belt through the forward facing slots of a rear facing shell. The instructions show a belt path for each orientation. Using the wrong path is not a legal installation.

R44 group 0 includes a lie-flat or lateral baby carrier as well as a rear facing carrier or baby seat. That is a published seat type, not a medical recommendation. A child who needs a lie-flat restraint because of a medical condition can also use a restraint designed for their needs, or a disabled person's seat belt, under the GOV.UK disability rule. A doctor can issue an exemption certificate if they cannot use a restraint at all.

Two rear facing seats need two legal positions. If the rear bench will not take both, GOV.UK's 'no room for a third child car seat' rule is about a third child, not about squeezing two seats into one ISOFIX pair. Use a car that accepts both installations, or move one child to a permitted front seat with the airbag off.

A carrycot that is not an approved child restraint is not a substitute for group 0. Look for the E mark and R129 or ECE R44.

On an R129 seat, after the child is over 15 months, and only if that seat or a different approved seat is labelled for forward facing at the child's height and weight. On an R44 seat, when a group 1, 2 or 3 seat that allows forward facing covers the child's weight.

Outgrowing a rear facing seat means the head sits above the shell, or the child exceeds the labelled height or weight. It does not mean they can sit unaided, or that they asked to see the road. If they still fit, rear facing remains legal.

A child under 3 may travel unrestrained in the rear of a licensed taxi or minicab if the correct seat is not provided. That is an exception, not a reason to skip a rear facing seat in your own car. Vans follow the same rules as cars.

nidirect repeats the airbag rule for Northern Ireland and the taxi exception for a child under 3 in the rear. The 15 month R129 rear facing threshold is described on the same nidirect page as the first i-Size stage. The penalty for a wrong restraint is the Northern Ireland figure of £60 and three points, not the Great Britain £100 fixed penalty.

The airbag is left on because the switch was forgotten after a valet or a service. Check it before every journey that uses the front.

The support leg sits on a storage trapdoor that collapses in a crash. The instructions say to lock the floor or move the seat.

The child is moved forward to 'see out' at 12 months on an R129 seat. That is a month and more too early.

A second-hand seat has no instructions and a faded label, so nobody can show it is approved or how it faces.

Myth: rear facing is only for newborns. R129 requires it until over 15 months and allows it far beyond. R44 group 0+ goes to 13 kg.

Myth: the front is always safer for a baby so you can watch them. The law does not rank seats that way. It forbids a rear facing seat in front of a live airbag.

Myth: a mirror on the rear headrest changes the legal facing direction. It does not.