The next seat after an infant carrier

Change when your child passes the seat's height or weight limit, or when the top of their head rises above the shell. Age alone isn't the signal. RoSPA's child car seat site says to keep a baby rearward-facing for as long as possible, and to move on once the seat has been outgrown.

Feet are the classic false alarm. RoSPA says dangling feet over the end of the seat aren't a reason to move a baby into a forward-facing seat. Cybex's page says the same about feet sticking out.

The signs a seat is outgrown

• Height. Your child has passed the top of the range printed on the seat.
• Weight. They've reached the limit. The Babymore Coco, Britax BABY-SAFE CORE and Cybex Cloud G all stop at 13 kg.
• Head. RoSPA says the top of the head above the top of the seat usually means it's time.

Don't move up early so they can "grow into" something. RoSPA warns against putting a child in a restraint that's too big for them. Worried about how your child sits or travels? Speak to your doctor or health visitor.

Forward-facing or stay rear-facing?

GOV.UK says height-based seats have to be rear facing until a child is over 15 months. After that, forward-facing is allowed. It isn't a target.

The NHS says: "Use a rear-facing car seat for as long as your child fits into it, as these offer better protection in the event of a car accident." RoSPA says: "Do not rush to move your baby into a forward-facing seat, rearward-facing is safer and gives better protection to their head, neck and spine in a crash." It also says keeping children rear-facing to around four is common in some countries, especially Sweden.

A tight budget doesn't have to mean turning your child round at 15 months. Price the rear-facing Shea 360 below first.

Budget and car size are real factors too. A forward-facing seat that's within the rules, correctly fitted and used every journey is a legitimate choice. Our plain guide to i-Size and R129 covers the rules behind this.

Four seats compared

Prices were checked on 3 November 2026. They're for the seat alone. Add the base for the Sirona and the DUALFIX before you compare. ADAC grades the Sirona 2.5 and the DUALFIX 3.2 on those bases, and lower is better. We could read no ADAC grade for the Shea or the Hazel.

Babymore Shea 360: rear-facing on a budget

The Shea 360 costs £179 with no separate base, the lowest price of these four for a seat that stays rear-facing. Babymore rates it rear-facing from 40 to 105cm, up to about 4 years, with a 5-point harness. It says not to face it forward before 15 months. Babymore was selling it below this list price when we read the page.

It spins 360 degrees on Isofix and a supporting leg, so check your car takes both. At 13.7kg by Babymore's figure, it's another seat to leave in one car.

Babymore Hazel: forward-facing only

The Hazel is the lowest-priced of these four at £119, and needs no separate base. It only faces forward, so it's for a child over 15 months who has reached the bottom of its height range. That means a wait if your baby outgrows the carrier early, and it ends rear-facing sooner than the NHS and RoSPA lines above would have it.

Babymore says it fits with Isofix and a top tether, so check your car has both. It lasts for years on paper, because it turns into a booster once your child moves on to the car's belt, which Babymore puts at 105cm. That's a lot of years for the money.

Cybex Sirona G3: rear-facing to 105cm

The Sirona G3 costs £239.95 plus a base. Cybex says it can stay rear-facing across the range in the table, and it spins 360 degrees, which Cybex says makes it easier to get your child in and out.

ADAC's autumn 2026 test gave the Sirona G3 with Base G3 a 2.5, on a scale where lower is better. Cybex also claims "Best in Class" from that test, and that's Cybex's wording. The whole thing is heavy at 13kg with the base, according to Cybex, so it's a seat to leave in one car.

Already have Cybex's Base G from a Cloud G? Cybex says the Sirona G3 fits it, which could save you the base.

Britax DUALFIX 5Z: weaker ADAC grade

The DUALFIX 5Z costs £279 plus the VARIO BASE 5Z. Britax says the base rotates 360 degrees and that the seat runs until your child is four. ADAC says it can't be fitted with the car's seat belt, so your car needs Isofix points. It lists the seat at 5.2kg and the base at 8.1kg.

ADAC tested the seat on that base in May 2026 and gave it 3.2, with a low injury risk in a side crash and a raised one in a frontal crash. That sits below the Sirona's 2.5.

There's a second thing to know about that base. In October 2026, ADAC and Stiftung Warentest reported that a different seat, the BABY-SAFE PRO on the VARIO BASE 5Z, failed in a frontal crash test in its reclined position, when the buckle on its harness opened. Britax has since voluntarily recalled some BABY-SAFE PRO seats made between 26 December 2025 and 30 September 2026. Its notice puts the result down to buckles from a single batch, and says it came only in the most reclined position on that base. Those are Britax's words. If you own a PRO, the notice explains how to check yours.

None of that names the DUALFIX 5Z. We found no current recall for this model on 3 November 2026. Britax's notices also list a 2018 recall of certain older classic DUALFIX seats, and Britax says other versions aren't affected. I'd ask Britax directly about the base before buying this combination.

Which I'd pick

For rear-facing use, the Sirona G3. It matches the DUALFIX at 105cm, its limit is 19 kg against 18 kg, and its ADAC grade is better. If money is the main thing, the Shea 360, which keeps your child rear-facing to 105cm. The Hazel costs less again, and it's a legitimate choice once your child is over 15 months and within its height range, with a check that your car suits it. I wouldn't rush any of them while the current seat still fits.

All four go in your car before you commit, if the shop lets you. RoSPA says not all seats fit all cars. Reminder from choosing a first car seat: second-hand seats aren't the place to save. The NHS says "Do not buy a secondhand car seat". Other options are in the car seat list.

Sleep in the bigger seat

Older babies nap in the car too. The Lullaby Trust says car seats aren't a main sleeping place, and to move a sleeping baby to a firm, flat surface when you arrive. For every sleep at home, the NHS advice is on the back, on a firm, flat mattress, in a clear cot, and in the same room as you for at least the first 6 months.