Toddler car seat

Fact-checked by experts from Good Egg Safety

If you have an infant car seat then you’ll need to move your child to a bigger car seat at around 12 to 18 months. There are a variety of products out there, all with different price tags, so how do you know which seat is best for you and your toddler? We spoke to car seat safety experts to find the information you need.

This buyer’s guide will cover

  1. When should I move to a bigger car seat?
  2. What types of car seats are available for toddlers?
  3. What does extended rear-facing mean and why is it important?
  4. What are i-Size car seats?
  5. What are the differences between R44 and R129 (i-Size) car seats?
  6. Fitting your car seat
  7. Questions to ask before buying a car seat
  8. Other things to consider

In a hurry? Here are our top tips for buying a toddler car seat

  1. Don’t move your child up to the next stage seat too early – it’s safer to let them reach the limit of their infant car seat before moving them to a bigger one
  2. Keep them rear-facing for as long as possible because it is the safest way to prevent serious injury in a collision
  3. Check that your new seat will fit all the cars you want to use it in
  4. Try to find a seat that has easily removable covers – toddlers will be toddlers after all

Watch our expert-led FAQ video with Good Egg Safety

When should I move my child to a bigger car seat?

There’s no rush to move your child up to a bigger car seat until they’ve reached the maximum limit of their smaller seat.

So if you think your child may be outgrowing their baby car seat, it’s worth checking what the limit is before moving them up to the next stage.

What type of car seats are available for toddlers?

1. i-Size seat: Extended rear-facing seat

extended rear facing car seat
  • Suitable from 67 to 105cm (approximately six months to four years) – some can even be used from birth
  • Can typically be used in both rearward and forward-facing positions, most allowing you to rear-face up until the age of four
  • Fitted with an ISOFIX base


  • Specially designed for toddlers
  • Helps you to keep your child rear-facing for as long as possible
  • If you have an i-Size infant carrier, you may be able to reuse the base for your toddler seat


  • More expensive than other types of seat
  • Large and heavy – not designed to be moved between cars
  • Requires ISOFIX points in your car

2. Combination seat: Group 0+/1, Group 0+/1/2 and Group 0+/1/2/3

joie every stage car seat

  • Group 0+/ 1 used from birth to 18kg (approximately four years)
  • Group 0+/1/2 used from birth to 25kg (approximately five or six years)
  • Group 0+/1/2/3 used from birth to 36kg (around 12 years old)
  • ISOFIX and seatbelt fittings available


  • Adaptable – the seat will grow as your child does
  • Some are extended rear-facing seats


  • Large and heavy, not made to switch between cars
  • Can be complicated to customise

3. Forward-facing car seat: Group 1

Forward facing group 1 seat
  • Used from 9kg to 18kg (approximately nine months to four years old)
  • Forward-facing only – it’s recommended that you keep your baby rear-facing until at least 15 months
  • ISOFIX and seatbelt fittings available


  • ISOFIX and seatbelt routing models available
  • Usually smaller and lighter than i-Size and combination seats


  • You'll need to buy another seat when your child is around four years old

4. High-back booster with harness: Group 1/2/3

Forward Facing booster seat with harness - Group 1/2/3 car seat
  • Used from 9kg to 36kg (approximately nine months to 12 years old)
  • Forward-facing only
  • ISOFIX and seatbelt fittings available


  • Seat adapts as your child grows
  • Usually smaller and lighter than i-Size and combination seats


  • Can be complicated to customise
  • Usually only forward-facing

What does extended rear-facing mean and why is it important?

In a collision, a child’s head can be thrown forward with great force in a forward-facing seat because the body is held in place by the harness but the head and neck are not. An infant’s neck muscles are weak and their head is disproportionately big when compared to their body, so this can cause serious injuries.

In a rear-facing seat, the force pushes the child into the seat, so the head neck and spine are protected, which greatly reduces the risk of injury.

In Sweden and many other European countries it’s the norm for children to remain rear-facing in cars up to around four years old and extended rear-facing seats are becoming more and more popular in the UK too.

While they can be more expensive, Claire Waterhouse, founder of Child Seat Safety, advises that you think about the types of journeys you often make.

Keeping your child in a rear-facing position as long as you can will be generally be safer for them, especially if you know you'll be driving a lot. It also depends on the size of your vehicle and how the seat is fitted.

What are i-Size car seats?

i-Size seats are seats that meet the R129 European car seat safety regulation that came into force in July 2013. The new regulation aims to increase the safety performance of all child car seats in three ways:

  1. It has raised the minimum collision testing standard – in addition to the front collision and roll-over tests that R44 car seats have to undergo, R129 seats must also be tested in side-impact collisions
  2. There is less margin for error when fitting an i-Size car seat into a car than a traditional seat belted car seat because the seat is attached using ISOFIX points
  3. i-Size car seats are height-based rather than weight-based – this makes it easier to know when a child needs a bigger seat.

At the moment, both R129 and R44 car seats are available to buy and legal to use in the UK, but eventually i-Size will replace R44.

toddler in car seat

What’s the difference between R44 and R129?

The key differences between R44 and and R129 (i-Size) are:


  • Classification is based on weight
  • Side-impact tests aren’t required, although some manufacturer’s do them anyway
  • Frontal collision testing is done at a speed of 50km/h and rear impact collision testing is done at 30km/h – you’ll be able to check for compliance here by looking for an ‘E’ label on the car seat
  • Seat can be fitted using a seatbelt or ISOFIX fittings
  • Seat must be rear-facing until the child weighs 9kg (around nine months)


  • Classification is based on height
  • Side-impact tests are always required
  • Seat can only be fitted using ISOFIX
  • Seat must be rear-facing until the child is older than 15 months

Side-impact protection, which usually takes the form of padding around the headrest and sides, absorbs the force of the impact in the event of a car accident to prevent serious head injuries

You should look out for this when assessing the overall crash test rating of a particular seat before you buy.

Fitting your car seat

When it comes to toddler car seats, or any kind of car seat for that matter, it’s always safer for them to be fitted in the back seat. It's vital that your seat is fitted correctly and securely every time it is used and it should never be modified to fit into your car.

Check the car seat manufacturer’s vehicle compatibility list before you choose a preferred seat and keep hold of the instruction booklet so that you always have something to refer to.

Infant and toddler car seats are fitted using a seatbelt or ISOFIX fittings, both of which are equally as safe.

With ISOFIX, however, there is less margin for error, but you can only use this type of fitting if your car has it, and not all do (check for labels in the base of the seat).

Read more about ISOFIX here.

Questions your retailer should ask you when fitting a car seat

Nick Lloyd, Acting Head of Road Safety for The Royal Society of the Prevention of Accidents (RoSPA), recommends that, when choosing your seat, you go to a retailer with trained car seat fitters.

If you can, get a car seat fitter to show you how to fit the seat correctly, then fit it yourself with their guidance.

It’s also a good idea to double check the fitting video provided by the seat manufacturer, just to be 100% confident you are doing it correctly – even retailers you deem trustworthy can get it wrong.

As such, you should make sure that your chosen retailers asks the right things. Last year, Good Egg Safety conducted undercover testing and found that 89% of retailers failed to ask the key car seat questions.

  1. Child’s weight
  2. Child’s height – if you’re buying an i-Size car seat
  3. Child’s age
  4. Your vehicle make and model and details for other vehicles you’ll be using the car seat in – not all car seats fit in all cars
  5. If your vehicle has ISOFIX – only for an ISOFIX seat
  6. If your vehicle has underfloor storage – some seats may not be suitable in cars that have underfloor storage
  7. If your seat has a top tether – a piece of seatbelt material with a hook on the end that attaches to an anchor point behind the back seat

Read Good Egg Safety's full car seat safety assessment form used for all retailers.

car seat safety harness

What else to consider when buying a toddler car seat

1. Make sure the seat is comfortable

If you’re likely to go on long car journeys with your toddler in tow, then comfort is key. Look for adjustable padded headrests, leg support and different recline positions.

Also make sure your toddler doesn’t overheat in the seat. Refrain from dressing them in bulky jackets or padded clothing – instead, opt for a jumper or cardigan, or lay a jacket or blanket over the straps to keep them comfy and warm. Thick clothing could also cause the harness to be fastened incorrectly.

2. Don’t use backless booster seats for toddlers

As of February 2017, a booster seat law came into force which states that children weighing less than 22kg or shorter than 125cm tall should not sit on booster cushions.

Backless booster seats or cushions aren’t meant for toddlers – they offer no side impact protection and can only be used when your child reaches the height and weight limit of your toddler car seat, which will usually be around the age of four, but do check the manufacturer’s guidelines.

If you already own a backless booster that was designed and manufactured before 9th February 2017, you are still allowed to use it. However, it is always recommended to use a high-back booster seat rather than a backless booster as they offer so much more protection for your child and also position the seatbelt correctly on their shoulder.

All in-one (3-in-1) car seats are an option if you want yours to go the distance. These transition from a forward-facing toddler seat to a high-back booster, but check that they fit in your car first.

3. How much do they cost?

Prices for toddler car seats can vary enormously. Many big brands do their own independent tests at higher speeds than the R44 regulations, and a lot of the larger rear-facing-only car seats have passed the Swedish Plus Test, which is the world's strictest car seat test. These tests can cost a lot of money, which can be reflected in the price of the seats.

There are some good toddler car seats on the market which may cost less, but have undergone strict crash tests, though, so do check their crash test ratings before you buy.

4. What about secondhand seats?

The cost of a car seat can be prohibitive, but is it possible to use a secondhand seat? A car seat's main job is to protect your child in the case of a collision. And, for that purpose, it is a single use item.

In other words, you can use a car seat until you have a collision, but as soon as that happens the seat has to be thrown away and replaced, even if it looks fine from the outside. The cost of replacing a car seat is covered by your car insurance as are the seatbelts. Any seatbelts in use during a collision should also be replaced.

Good Egg recommends never buying a secondhand seat in case there is damage, whether from a previous collision or otherwise. In the case of older seats, they may not have gone through the latest crash tests either.

5. Five-point harness or impact shield?

Five-point harness

A five-point harness is designed to restrain your child within the protection of the car seat if there is an impact.

It must be buckled correctly and tightened so the straps are flat to your child’s chest. You should only be able to get a maximum of two fingers between the harness and your child's collarbone. The straps should be as level with the shoulders as possible, but if they are between heights, they can be slightly above their shoulders in a forward-facing seat and slightly below their shoulders in a rear-facing seat.

Selecting the correct harness height and doing the harness up firmly will prevent your child from wriggling their arms out. The harness attaches above each shoulder, on both sides of the waist and between the legs.

Most combination car seats with a harness have planned ahead for when it converts to a high-back booster. Either the harness is entirely removable (just don’t lose it if you’re planning on using this seat with future children too!) or you can tuck it behind the back cushion, meaning it’s out of your child’s way and doesn’t affect their comfort in the chair either.

Impact shield

An impact shield is held in place using a standard three-point seatbelt and is only found on forward-facing seats – they can only be used if your child weighs 9kg or more.

In the event of a front or rear-end collision, the upper body curls over the shield, meaning the force on the toddler’s spine and neck is significantly reduced.

6. Adjusting combination car seats

Combination car seats are designed to grow with your child, so tend to include various adjustable features. But always double check how easy it is to adjust these before you buy.

It’s all very well having 10 different heights you can adjust the headrest to, but if it’s super stiff and requires you to take the seat out every time, this might be more of a faff than it’s worth.

7. How easy is the car seat to clean?

Toddler and mess tend to go hand-in-hand. Whether it’s juice spills, crushed up food or other explosions we’d rather not imagine, invest in a car seat that’s easy to clean – think wipe-clean fabrics and removable covers that can be thrown in the washing machine at a moment's notice.

If you can’t remove the cover, take the car seat out of the car and spot-clean any stains.

Some manufacturers also allow you to purchase separate seat covers for those days when the one you've washed just won't dry.

Ready to shop? Check out our toddler car seat reviews

Useful resources

About Mumsnet Reviews

All Mumsnet product reviews are written by real parents after weeks of research and testing – this includes recommendations from the Mumsnet forums. We work hard to provide honest and independent advice you can trust. Sometimes, we earn revenue through affiliate (click-to-buy) links in our articles. However, we never allow this to influence our coverage. Read our how we test page to find out more.

All prices correct at time of publication

Photo credit (images 4 and 5): Good Egg Safety CIC


You might also like

Best double buggies

Two to travel? We're here to help

We review the best double buggies

Car seat regulations

All the information you need, made simple

UK car seat laws explained