In a nutshell

Sturdy Group 1/2/3 car seat that uses ISOFIX and top tether for safe installation, and has added safety features including a side impact system and a pelvis protector - but it is heavy

What we tested

  • Ease of installing
    A star rating of 4.5 out of 5.
  • Comfort
    A star rating of 4.5 out of 5.
  • Safety features
    A star rating of 5.0 out of 5.
  • Style
    A star rating of 5.0 out of 5.
  • Durability
    A star rating of 5.0 out of 5.
  • Worth the money
    A star rating of 4.5 out of 5.
Overall Rating
A star rating of 4.8 out of 5.


  • Lots of neat extra safety features, spacious, comfy


  • A bit heavy to lift

Key features of the Britax Advansafix III SICT Group 1/2/3 car seat:

  • Age suitability: 9 months to 12 years (9-36kg)
  • Installation: ISOFIX and top tether
  • Features: Multi-stage car seat; side impact protection; harness to 18kg; Secure Guard pelvis protection
  • Cost: £250

Britax started life in Britain in 1938 and merged with German car safety counterpart Römer in 1978, and the company has been making car seats for over 50 years

The Advansafix III SICT was released in February 2017 as Britax's latest answer for parents who want a car seat that will grow with their child, without compromising on safety.

Released at the same time as the Britax Evolva 1-2-3 SL SICT (catchy names, eh?), both seats are upgrades on previous editions and suitable for children aged from 9 months to 12 years old.

Both end the problem of your little one outgrowing their seat, but with quite different features.

The Advansafix III SICT is packed with lots of extra safety features not always found on your average car seat; it even has a 'top tether', which is like a seat belt that loops over the back of your car's actual seat and acts as an extra level of protection on top of the ISOFIX.

Other car seats in a similar price range include the Cozy N Safe Excalibur (£249), which has a harness to 25kg, the Bebylux Alexa car seat (£295), and the Kiddy Phoenixfix 3 (£225), although this is only suitable to 4 years.

Meanwhile, the Joie Bold Group 1/2/3 car seat is cheaper at £175, and also offers ISOFIX and top tether installation.

I tried the Advansafix III at the same time as the Britax Evolva 1-2-3 SICT SL, which was launched at the same time. They're both Group 1/2/3 car seats but with different features, and the Evolva is £40 cheaper.

The Evolva is noticeably lighter and therefore easier to transport between vehicles, if you're a two car family. It doesn't have a top tether though or the SecureGuard. It's got ISOFIX though, and is strong, well made and spacious. As a buyer you'd have to weigh up whether you want a seat that's lighter and easier to transfer or one with extra safety features.

You can buy the Britax Advansafix III SICT from John Lewis and Kiddicare.

Watch 5 things you need to know about the Britax Advansafix III SICT car seat

What's in the box?

  • Car seat
  • ISOFIX guides
  • Side impact shields
  • Instructions

What were your first impressions?

As soon as you get it out of the box you can see it's a luxury seat. It's sleekly designed, the fabric looks comfy and its shell offers a lot of coverage without it looking cumbersome.

Is there anything unique about the seat?

Britax has developed its new SecureGuard feature, an extra contact point for the car's seat belt, to be used when your child is at the correct age. It protects your little one's abdomen and ensures correct seatbelt positioning.

Also, I've never come across a seat with a top tether before. It looks just like a V shaped seat belt, which comes out the back of the car seat, loops over the head rest of the car's actual seat and hooks on to an anchor point in the car. It's something which adds an extra bit of safety reassurance for parents.

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Who would the seat be most useful for?

Parents who want a car seat that lasts until their child is 12 (when they no longer require one), and who also want extra safety features.

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Is there anything you would have wanted to know before buying the car seat?

You need to check that it's compatible with your car before you buy.

How does it install in the car?

It's an ISOFIX seat, so for those of you already acquainted it's quite simple - click the ISOFIT bars into the ISOFIX fittings in between the backrest and seat of your car so that they are locked into place.

The Advansafix III has an additional 'top tether', which you'll find in a pocket on the back of the car seat. This is a V shaped tether (it's like a seatbelt) with a hook on the end. This goes over the top of your car seat and hooks on to the eyelet on the back of your seat (all cars are different so please check the car seat is suitable for your car before you buy!).

Is it easy/hard to install?

Putting the seat in the car was very simple. The ISOFIT bars lock into place and the top tether does too. The only issue is finding where the car's anchorage point is, which may involve a quick rummage through the boot to find it on the back of the seat.

Does it feel sturdy?

Yes, it's really solid. Some highbacked booster seats I've seen seem really basic and thin, but not this one. It's strong. The shell of the seat also looks like it'd offer quite a breadth of protection.

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How comfortable does it feel?

It's got lots of nice padding, so is very comfy.

How is strapping your child in?

There are two options, depending on the weight of your child.

In Group 1 (up to 18kg) there is a 5 point harness, which is simple once you've got the knack.

In Groups 2 and 3, you can fold away the harness and use the car's own seatbelt.

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What I really like is an extra little feature Britax has built into the seat, which it calls the SecureGuard. This is an extra 'contact point' for the seat belt to protect your child's abdominal region. So, like the 'hooks' on each side of the seat, it stops the belt digging into your child's body or slipping in to the wrong position. Britax says research on test dummies reveal the SecureGuard reduces abdominal forces in the event of a frontal collision by up to 35%.

There are even 'performance' chest pads on the 5 point harness for extra comfort and also to distribute the force of an impact.

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What's the headrest like?

It's nice and padded, and positioned well, so that when your child nods off their head doesn't constantly slip off to the side.

How many positions does the headrest have?

11. It adjusts using one hand too, which is very useful.

How many seat positions are there? Is it easy to adjust the seat?

It has 3 reclining positions, which can be changed with a quick pull of lever.

How portable and easy is it to get in and out of the car?

The ISOFIT fittings work smoothly but, at 11.2kg, the seat is a bit heavy to lug around too much.

What do you think of the design?

I really like it. It's simple yet attractive. It's obviously been designed with care.

What do you think of the size of the car seat?

It measures 47cm across, by 54cm in depth and the height of it adjusts from 56-82cm.

The seat in which the child actually sits is quite wide, but in the car, the seat itself doesn't take up too much space.

Do you think your child will fit into the seat until they're 12?

Yes, the back rest goes up quite high, and so does the head rest. The seat is wide too. I think it's well designed to accommodate a growing child.

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How does the side impact system (SICT) work?

You get them included in a separate little box. They're like plastic shells which you just clip in to place according to which side of the car your child is sitting. You only put it on the side closest to the door.

They're designed to absorb the energy if you're in a crash.

Is it easy to clean?

Yes. A quick sponge clean worked. If the mess is too much for a mere sponge, you can take off the cover and put it in your washing machine.

Is the product value for money?

You can get many car seats for less than £250, but price shouldn't be the sole factor you base your purchase on. The Advansafix III has lots of neat safety features and lasts up to 12 years old, so I think it's a good investment.

Do you have to buy lots of additional extras?

You don't have to but there are some available – you can buy the summer cover (£30), thermal cover (£45) and a car seat saver (£25).

What did you think of how the various parts adjusted?

The parts are really easy to move. It has an intuitive design, so is easy to work out.

MadeForMums verdict:

The Advansafix III has many great safety features, is strong and sturdy, yet comfy. It's a really well made car seat.

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Product Specifications

ModelAdvansafix III SICT car seat
Suitable for
Child age (approx)9 months to 12 years
Child weight9kg to 36kg
Dimensions & Weight
Removeable cover for washingYes
Recline positions3
Height adjustible headrestYes
  • Side impact protection
  • Secure guard seat belt holder
  • 5-Point harness to 18kg
  • Top tether
Optional extrasSummer cover (£30); Thermo cover (£45); Car seat saver (£25