A car seat is the one piece of baby equipment you can’t afford to get wrong. It only protects your child if it suits their size, fits your car and is used properly on every single journey. This guide brings together everything you need in one place: how to choose a seat, how to fit it, how to check the harness, how long to keep your baby rear-facing and how to look after the seat as your child grows.
Use a car seat on every journey, choose one that matches your child’s height and weight and fits your car, and fit it so it moves no more than about an inch at the belt path or ISOFIX points. Keep the harness flat and snug (you shouldn’t be able to pinch any webbing at the collarbone), keep your baby rear-facing for as long as the seat allows (and at least until they’re over 15 months in an i-Size seat), avoid second-hand, expired or unapproved accessories, and don’t leave a baby in a car seat for more than two hours at a time. In the UK, children must use a car seat until they’re 12 years old or 135cm tall, whichever comes first.
In the UK, children must use the correct car seat until they reach 12 years old or 135cm in height, whichever comes first. GOV.UK sets out the rules, including the few limited exceptions, such as some taxis and minibuses. A properly used seat is one of the most effective ways of reducing the risk of serious injury in a collision, and that applies to short trips to the shops as much as long motorway drives.
Browse Babymore’s car seats to see the stages available, from newborn seats through to boosters.
UK seats are one of two types. i-Size (R129) seats are based on your child’s height, and weight-based (R44) seats use weight groups. Both are legal and both are safe when used correctly, but the limits differ, so always read the label on your seat.
As a rough guide, newborn seats suit babies from birth up to around 13kg, and the next stage takes over from there. Children grow quickly, though, so check the limits regularly rather than going by age. Signs your child has outgrown a seat include the top of their head reaching the top of the shell, shoulders above the highest harness slots, or reaching the stated weight limit.
Our guides on understanding car seat limits, choosing a car seat and the UK car seat regulations explain the stages in more detail.
Not every seat fits every car. Seat shapes, belt buckle positions and ISOFIX points vary, so a seat that’s perfect in one car can be awkward in another. Before you buy, check the manufacturer’s vehicle compatibility list or, better still, try the seat in your car. Many retailers offer fitting checks, which are worth taking up, especially for a first seat.
If you’re considering a travel system, Babymore’s baby travel systems pair a pushchair with a car seat, and the MeMore travel systems are worth a look if you want one set-up for the car and the pavement.
A seat can be well designed and still fail to protect your child if it’s fitted loosely. There are two main ways to fit a seat:
Whichever you use, read both the car seat manual and your vehicle handbook. Once the seat is in, hold it at the belt path and give it a firm tug side to side and front to back. It shouldn’t move more than about an inch. Check the recline, too: many seats have an angle indicator, and a newborn who’s too upright can slump forward and struggle to breathe.
The harness is what holds your child in the seat, so it needs to be right every time.
Our guide on how tight a baby car seat harness should be explains the check step by step.
Rear-facing seats cradle the head, neck and spine and spread the force of a frontal crash across the whole back of the seat, which is why many experts advise keeping children rear-facing for as long as the seat allows. For height-based (i-Size) seats, the law says your child must be rear-facing until they’re over 15 months old.
Treat 15 months as the minimum rather than the target, and keep your child rear-facing until they reach the seat’s height or weight limit for that position. Our guide on when a baby can face forward in a car seat in the UK has the details.
If you ever need to fit a rear-facing seat in the front passenger seat, you must deactivate the front airbag first. Where you can, use the back: Babymore’s guide to the safest position in the car for a baby’s car seat explains why the rear middle seat is often considered safest and what to check if you need to use another position.
Bulky coats and snowsuits are one of the easiest ways to end up with a loose harness. The padding compresses in a crash and leaves slack in the straps. Dress your baby in thin, snug layers, tighten the harness, then put a blanket over the top. Our guides on car seat tips for bad weather and car seat safety when the clocks go back cover cold-weather journeys and darker mornings.
Young babies shouldn’t spend long stretches in a car seat. The semi-upright position can affect breathing and put pressure on the spine, which is why it’s commonly advised to avoid leaving a baby in a car seat for longer than two hours at a time. On a long drive, plan a stop at least every two hours so you can take your baby out, feed them and let them stretch. The advice also applies to using an infant carrier as a place to nap at home or on the pavement: when you arrive, move your baby to a flat, firm sleep surface.
A second-hand seat may look perfect and still have hidden damage from a crash, poor storage, missing parts or an older safety standard. You can’t tell by looking. Unless you know a seat’s full history, such as one handed down by a trusted friend or family member who can confirm it’s never been in an accident, buying new is the safer choice. Our guide on whether it’s safe to buy a second-hand car seat explains what to ask.
Plastics and webbing degrade over time, so manufacturers set a lifespan for each seat, often a number of years from the date of manufacture. Look for the date on the seat’s label or in the manual, and replace the seat when it reaches the end of its life, even if it looks fine.
Extra padding, inserts, strap covers, sunshades and seat protectors are easy to buy, but car seats are crash-tested the way they’re designed to be used. Which? advises that adding accessories not approved by the manufacturer could compromise the seat’s safety or void its warranty, and recommends using only products supplied or recommended by the manufacturer. If you’re unsure whether something is approved, leave it out.
A few minutes of care keeps a seat working as it should.
Most car seat problems come down to a handful of habits: a loose installation, a loose or badly positioned harness, turning a child forward-facing too early, a bulky coat under the straps, or keeping a seat that’s been outgrown. Our guide to common car seat mistakes covers all 14 and how to fix them, and common car seat issues looks at the problems parents run into most often.
Car seat safety isn’t about one big decision. It’s a set of small, repeatable habits: choosing the right seat, fitting it carefully, checking the harness every time, keeping your baby rear-facing for as long as possible and replacing the seat when it’s outgrown, expired or been in a crash.
Ready to choose? Browse Babymore’s car seats or our baby travel systems, or start with our guide to choosing a car seat.
