The short answer
Use an approved child seat that fits your child and car. In the UK, a child seat is normally required until age 12 or 135cm, whichever comes first; NHS advice is to keep a child rear-facing for as long as they fit the seat.
In this guide · 12 sections
Keep in mind
- Use the correct approved seat for your child’s height or weight and your vehicle.
- UK law normally requires a child seat until age 12 or 135cm, whichever comes first.
- NHS advice is to keep children rear-facing for as long as they fit the seat.
- Fit and use the seat exactly as its instructions say; never use a rear-facing seat in front of an active air bag.
Which way should a 31–36-month-old travel?
For safety, keep your child rear-facing for as long as they fit the seat; rear-facing seats offer better protection in a crash. Follow the seat’s height or weight limits and instructions.
UK law requires an appropriate child seat until a child is 12 or 135cm tall, whichever comes first. The legal minimum and safety advice are different: age alone is not a reason to turn a seat.
When can you use a forward-facing seat?
UK-approved height-based seats must be rear-facing until a child is over 15 months, but NHS advice is to keep using a rear-facing seat for as long as the child fits.
When the rear-facing seat limit is reached, use a suitable approved seat and follow its instructions.
How should the harness fit?
The harness should be snug against your child, with no loose slack.
Follow the seat manual for strap height and adjustment. If the seat has a chest clip, use it as directed by the manufacturer.
Where should the straps sit in a rear-facing seat?
The correct strap position varies by seat. Check the manual and use the harness slots specified for rear-facing use.
Do not change the seat’s direction or harness setup based only on age or a general rule.
How can you check the installation?
Fit the seat according to both the car and seat instructions, and make sure it is compatible with your vehicle.
If you are unsure, ask a trained child-seat checker or your local road-safety team for help.
What should you know about a forward-facing seat?
Once your child uses an approved forward-facing seat, follow its instructions for the harness and any support leg or top tether.
Check the vehicle manual for the approved anchor points.
Can your child wear a thick coat in the seat?
Bulky coats can compress in a collision and leave the harness too loose. Use thin layers and tighten the harness over them.
You can put the coat or a blanket over the child after buckling them in securely.
Where should your child sit?
Use an appropriate child seat in the rear of the car where possible.
Never fit a rear-facing child seat in a front passenger seat with an active air bag.
What can you check today?
Check your child’s height and weight against the limits on the seat label and in its manual. Keep them rear-facing while they fit the seat.
Check that the seat is installed as instructed and the harness is snug. Get help from a trained checker if you are unsure.
When to seek support
Some signs need emergency help; other concerns can be discussed with your child’s healthcare team.
- The seat does not fit the child or vehicle according to its instructions.
- Harness is loose, twisted, or incorrectly positioned.
- A rear-facing seat is placed in front of an active air bag.
- You are unsure whether the seat was installed correctly.
Sources used for this guide
- American Academy of Pediatrics / HealthyChildren.org — HealthyChildren – Rear-Facing Car Seats for Infants & Toddlers
- American Academy of Pediatrics / HealthyChildren.org — HealthyChildren – Car Seat Safety Checkup: 10 Questions to Consider
- American Academy of Pediatrics / HealthyChildren.org — HealthyChildren – Rear-Facing Car Seats for Infants & Toddlers
- American Academy of Pediatrics / HealthyChildren.org — HealthyChildren – Car Seat Safety Checkup: 10 Questions to Consider
- www.gov.uk — regional guidance
- www.nhs.uk — regional guidance
English editorial review:
The English text and regional guidance have been checked editorially. This is not an individual clinical assessment.
Luluna provides general parenting information. It does not diagnose conditions or replace your child’s healthcare professional.
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