This child car seat has passed the regulatory tests required by ECE R129/i-Size to be sold as suitable for children from 40cm to 85cm, which is from birth to 15 months old.

But in our own tests, conducted at higher speeds and forces than the standard requires, this seat scores poorly in frontal impact when used with the base and connected via Isofix.

When the seat is set up in an inclined position, the buckle of the shoulder harness opens and the dummy is thrown through the vehicle. These issues weren’t found when the car seat was set up with the seat in a fully upright position or when installed into the vehicle using the three-point seatbelt.

Britax has issued a recall for this car seat for certain models manufactured between 26 December 2025 and 30 September 2026. Read our news story for details of the barcode numbers and next steps.

Britax RömerBaby-Safe Pro + Vario Base 5Z

i-Size baby
Isofix and vehicle seat belt

£349Typical price

Test score

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Britax Römer claims its Baby-Safe Pro + Vario Base 5Z is its lightest and most innovative infant carrier yet. It says its ‘Ergo Recline’ feature means your baby has a flatter and healthier position to travel in, and it even has a ‘Healthy Back’ Seal of Approval from Aktion Gesunder Rücken – the German back health association. Unfortunately, it fails to get a seal of approval in our crash tests – we encountered some catastrophic failures in our tests, and you can find out more information on them in the Safety Alert or by reading the full review.

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What's included?

What is it?
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Is it easy to fit?
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KEY TEST RESULTS
Safety rating
Fitting in car
Comfort of your child

Oct 2026First reviewed by Which?
May 2026Released

The overall Which? test score is made up of the following star ratings, all determined by our rigorous lab tests.

Two child safety seats in the back of an orange van, each holding a crash test dummy with green heads.

How we test baby and child car seats

6 Oct 2026

Safety rating

How we test safety rating

The overall safety score is made up of the results of crash testing (front crash; side crash) seat design, stability in the car and belt routing. Our crash tests go beyond the legal minimum requirements for UK car seat regulations and are conducted at higher speeds and forces than the regulations require. We feel our tests more accurately reflect what could happen in a real life crash.

Fitting in car

Overall
Buckling up
Avoiding misuse and instructions
Cleaning
Space required in car

How we test fitting in car

Fitting and using includes: How easy it is to install the seat correctly in the car. How easy it is to strap a child securely into the seat. How well the seat is designed in order to prevent incorrect use. How easy the seat cover is to remove and wash. How little space the seat takes up in the car and how comfortable your child is in the seat.

Ergonomics

Overall
Comfort of your child

How we test ergonomics

Our experts conduct an ergonomic assessment of each seat to make sure your child will be in the best position when travelling, along with the level of padding and support. Our tests also reveal how much space this car seat takes up in the back seat of a car and how easy it is to get your child in and out of the seat. Plus, our eagle-eyed car seat experts will check whether this seat affects how much space any front passengers have. This assessment was introduced to our site in May 2015. If a seat does not have this score, it was tested before May 2015.

General
Height of child	40cm-85cm
Seat size	i-Size baby
Age group	Baby
Direction of travel	Rearward facing
Extended rear-facing seat	No
Installation type	Isofix and vehicle seat belt
Harness or shield seat	Harness
How is the child held in the seat?	3 point harness
Manufacturer URL	https://www.britax-romer.co.uk/

Features
Adult seat belt	Yes
Isofix integrated into seat	No
Isofix base	Yes
Belted base	No
Type of Isofix	Isofix connectors and support leg
Swivel seat	Yes
Weight of seat (kg)	4.18kg
Weight of base (kg)	8.4kg
Part of a travel system?	Yes
Harness height adjustment	Moves with headrest
Adjustable headrest	Yes

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Britax RömerBaby-Safe Pro + Vario Base 5Z

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pros

cons

What's included?

How we test baby and child car seats

Safety rating

Fitting in car

Ergonomics

How this product's score compares with other child car seats we've tested

Suggested Alternatives

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Nuna

Cybex

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Britax RömerBaby-Safe Pro + Vario Base 5Z

pros

cons

What's included?

Test results

Specifications

Best Buys & Don't Buys

Suggested Alternatives

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Nuna

Cybex

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