Log in or register
My AA Account

Sign in to see your cover and request assistance online

Log in

Don’t have a My AA account?

You’ll need your policy or membership number

Create an account

Your Finances

Loans | Savings | Credit Cards

Your Driving Lessons

Book a lesson


A new standard for safer child restraints

Based on the standing height of the child, rather than weight

This new standard for car seats (ECE Regulation 129 (i-Size) doesn’t replace the more familiar Regulation 44 (R44) – it runs alongside it. So you can use child restraints approved to either R129 or R44, and you’ll come across both types in shops.


  • Overlapping weight groups (0-13kg, 9-18kg, 15-25kg and 22-36kg).
  • Can be confusing.
  • Can encourage you to switch your baby to forward-facing seat too early.


Seats can be used up to the max stature (natural standing height) of the child, specified by the seat manufacturer. Minimum requirements for i-Size:

  • Rear facing may be applied to any age of child.
  • Restraints for children up to 15 months must be rear facing.
  • Restraints for children up to 15 months must accommodate at least a child with a stature of 83cm.
  • Forward-facing seats mustn’t be designed to accommodate a stature below 71cm.
  • A convertible seat in rear-facing configuration must accommodate children up to at least 83cm in height.
  • i-Size seats can only be attached using ISOFIX anchorage points – there’s no option to install i-Size restraints using adult belts.

Why choose i-Size?

  • You’re more likely to know your child's height than their weight so it should be easier to tell if a seat is suitable.
  • i-Size seats keeps your children rear-facing for longer – rear facing is safer.
  • i-Size approval includes a side impact test so seats should offer better all-round protection.
  • ISOFIX should make fitting easier compared to seats fitted using adult belt

Check your handbook

i-Size child seats can be used in any 'i-Size approved' seating position and must be installed according to the car manufacturer's instructions.

Check your vehicle handbook first to see if any seating positions are 'i-Size approved' (not available in cars registered before July 2013)

Vehicle-specific ISOFIX

If your car doesn’t have any i-Size approved seating positions, you may still be able to use an i-Size child restraint on seats with ISOFIX anchorage points. This is only if the vehicle and seating position are included in a vehicle-specific application list, supplied by the child restraint manufacturer.

If you plan to use your child seat in more than one vehicle it’s important to check that all have i-Size approved seating positions or appear on a vehicle specific application list.

Buy breakdown cover

We get more people back on the road than anyone else