What is ISOFIX and how can parents use it?

What is ISOFIX and how can parents use it?

What is ISOFIX?

Car Seats are at the top of the baby shopping list and for a very good reason. They are an essential product for keeping your little one safe whilst you are on the go, in fact some hospitals won’t even let you leave if you are travelling by car without a car seat to drive home.

When buying a car seat for your child you’ll come across the term ISOFIX when you are doing your research. But what does it mean? We took a closer look at what this term means, how it works and why it is important.

In a nutshell ISOFIX means “International Standards Organisation Fix”. ISOFIX is the top-class level of car seat

safety on the market now to ensure your car seat is secured safely and properly. ISOFIX is a universal system designed in the 1990's for fitting car seats that uses attachment point built into the car rather than a seat belt which makes it easier to fit the car seat securely by reducing the risk of error.


ISOFIX became mandatory in all vehicles manufactured after Nov 2014 which required all new cars to be manufactured with ISOFIX fittings.

It’s worth noting that the ISOFIX law covers Group 0+ and Group 1 car seats, which is from birth to 4 years. While Group 2/3 (4-12 years) car seats are governed by a system called ISOFIT.

ISOFIT is another piece of jargon that pops up from time to time. What is it? When your car seat has an integrated restraint (harness or shield) it falls into the ISOFIX category. When your child reaches 105cm approx. 4 years of age your car seat may still connect to the ISOFIX points, but the adult seat belt does all the work.

What approved forms of ISOFIX car seats are available:

  • Universal – Uses either a top tether or foot prop (stabilizing bar), in addition to the connectors, to fix the seat to an additional anchorage point for forward-facing seats. Universal ISOFIX car seats should fit into most newer cars.
  • Semi Universal – Uses a top tether, foot prop and connectors but is not compatible with all cars. Can be used with forward and rearward-facing (i.e lie-flat) car seats.
  • Vehicle Specific – Uses only the anchor point to secure the seat. This method is vehicle specific and is only compatible with certain vehicles. Always check the suitability of the make/model of the chair on the manufacturer’s website.

Pros of ISOFIX.

ISOFIX minimizes the risk of incorrect installation. Child car seats fitted using seat belts are often installed and used incorrectly*. Isofix provides a solid, permanent connection between the car seat and the car body and it is proven to be outstandingly safe in tests.

Cons of ISOFIX

Not all ISOFIX car seats will fit in every car, so do your research before buying. This poses problems for two-car families who swap car seats between cars.

ISOFIX or Seat Belt - What's Safest?

The truth is that neither is more safe than the other when used properly. According to government testing standards, there aren't any safety-related advantages to using seat belts over ISOFIX / LATCH lower anchors, or LATCH lower anchors over seat belts, provided that the seats are installed correctly.

If we look at all data, crash test, real life usage, and habits, ISOFIX is far safer than installing a car seat with seat belt. With ISOFIX, virtually no mistakes are made, something which can not be said about seat belt installs.

*A study of Group 1 seats, conducted by the German Insurance Institute (GDV), found that 96% of seats fitted using ISOFIX were installed properly. In comparison, the same study found that only 30% of car seats were fitted correctly when the adult seat belt was used. This is because the seat belt anchor points vary in size, length and position from car to car, so creating a seat that fits perfectly in every car is virtually impossible.

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Both use the same wide, breast-shaped teat design — the difference is in how they handle air reduction. Closer to Nature has a built-in anti-colic valve in the teat that reduces air ingestion during feeds. Advanced Anti-Colic goes further, with a heat-sensing tube at the bottom of the bottle that actively vents air out of the milk before it reaches your baby. For most babies, Closer to Nature is plenty. For babies with more significant colic, wind, or reflux, Advanced Anti-Colic is the better choice.

Yes — the Closer to Nature range is one of the most recommended bottles for combination feeding. The wide, breast-shaped teat encourages the same broad latch breastfed babies use at the breast, reducing the risk of nipple confusion. Always start with a slow flow teat for a breastfed baby regardless of age, and introduce the bottle around three to four weeks once breastfeeding is well established.

For many parents, yes. The Natural Start glass bottle is made from premium borosilicate glass — odour-free, heat resistant, and very easy to sterilise. It's particularly practical in the newborn period when you're sterilising frequently and mostly feeding at home. The main trade-offs are weight and the risk of breakage. Many parents use glass at home and plastic when out and about.

Start with slow flow for all newborns — whether breastfed or formula fed. Move up to variable flow when your baby shows signs of frustration, takes too long to finish feeds, or falls asleep before finishing. Fast flow suits confident, efficient feeders from around six months. Always let your baby's cues guide the decision rather than age alone.

Yes — both ranges include anti-colic features. Closer to Nature has a built-in anti-colic valve that reduces air ingestion. Advanced Anti-Colic takes this further with an active venting system that removes air bubbles from the milk during the feed. For babies with significant colic, the Advanced Anti-Colic bottle is the stronger solution. For a more powerful anti-colic system, Dr Brown's bottles use a fully internal vent system that is clinically proven to reduce colic.

The Perfect Prep Machine makes a fresh, perfectly mixed, body-temperature formula bottle in under two minutes — safely. It delivers a shot of hot water (over 70°C) to kill bacteria in the formula powder, then tops the bottle up to the correct volume with filtered water at room temperature. The result is a safe, correctly mixed bottle at the ideal feeding temperature, every time. The Day and Night version adds a quiet pump and soft night light for night feeds. It requires replacement filters every three months — available at Babies.co.nz.

As a guide: 2–3 bottles for occasional bottle feeding of a breastfed baby; 4–6 for combination feeding; 6–8 for exclusive formula feeding. The Closer to Nature 260ml 3-pack is the most practical starting point as it gives you enough bottles for a full day without constant washing.

Yes — all Closer to Nature, Advanced Anti-Colic, and Natural Start glass bottles and teats are dishwasher safe on the top rack. Replace teats every two to three months or sooner if you notice any thinning, stickiness, or discolouration.

Shop the full Tommee Tippee range online at Babies.co.nz with nationwide delivery, or visit our Auckland showroom in East Tamaki. We stock bottles, teats, the Perfect Prep Machine, sterilisers, breast pumps, and the full Tommee Tippee range. Price Match available and 5% back in Rewards on every purchase.

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The key difference is anti-colic power. Dr Brown's internal vent system is clinically proven to reduce colic and is the stronger solution for babies with significant wind or reflux. Tommee Tippee's anti-colic valve (Closer to Nature) and heat-sensing tube (Advanced Anti-Colic) are effective for most babies but less comprehensive than Dr Brown's approach. On the other hand, Tommee Tippee is simpler to clean — fewer parts, no internal vent tube to wash — and the breast-shaped teat is widely regarded as one of the best for combination feeding. Read our full Dr Brown's buying guide →

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