What Are Group 123 Car Seats?

So, car seats are categorised by groups, or at least they were under the R44 regulation. This is the older, but still current regulation, and R129 (aka i-Size) is the newest, most up-to-date regulation. This unfortunately does not make car seats any easier to understand as they are now categorised differently. R129 regulated seats are now referred to by the age of child that will go into it – “birth to 15 months” or “3 to 12 years” for example. You can read more about regulations and their differences here.

We use 3 main categories to try and make this as easy as possible:


Babies are usually transported in infant carriers, which are solely rearward facing until they are approximately 15 months. Infant carriers are typically known as group 0/0+. We offer other options that may be used until 18kg (approx. 3 ½ to 4 years). These seats will be categorised as group 0+/1, or 40 to 105cm when looking at an i-Size seat.


Toddler seats (Group 1) will have an integrated harness or impact shield and will usually accommodate your child from 15 months to approximately 3 ½ to 4 years, or up to 105cm. We do offer Extended Rear-Facing seats which are suitable to 25kgs (approx. 5 ½ to 6yrs) if you wish to rear face for a long period of time, or if you have a larger than average child.


At approximately 4 years of age, or 6 years of age if you have rear-faced for longer, your child will move into a High-Backed Booster (HBB). These seats do not have a harness and instead ‘restrain’ your child using an adult lap and diagonal seat belt. HBBs are often referred to as Group 2/3 or suitable from 100 to 150cm.

Group 123 Seat

Now, a Group 123 seat is a different category yet again, as these will in fact be suitable for both toddlers & children. If this is an i-Size seat, it will most likely be referred to as seat suitable for “1 to 12 years”. But grouping these seats by age, although intended to make it easier, can cause difficulties as you still must make sure your child is a suitable weight/height for that particular seat.

Group 123 seats, or combination seats as they are commonly known, may be suitable from 9kg or about 76cm, right up to 36kg, 150cm or 12 years of age. Children should be in a car seat until 135cm or 12 years of age*. Group 123 seats are useful for a second vehicle as they tend to be more affordable, and it means not having to change your seat every so often. Childminders and Grandparents also tend to find combination seats to be useful instead of carrying different seats for different children.

Our Group 123 Seats

We have a selection of Group 123 seats available. When choosing your new car seat, you must confirm that the seat is suitable for your child’s weight and height, and that it is compatible with your vehicle. If you need advice on what seat is best for your situation, get in touch and chat to one of our experts.

*If you are not sure if your child has outgrown their seat, simply get in touch and our experts can advise further.

In Car Safety Centre Milton Keynes Showroom