12 common child car seat mistakes you’re probably making

Woman securing child into car seat

Tianna Nadalin

Posted January 12, 2023

All parents want to keep their kids safe on the road. But, when it comes to child car seats, many parents are putting their precious cargo at risk without realising.

Legally, children must travel in a car seat, either rear-facing, forward-facing, or a booster seat, until they are seven years old.

Despite high levels of child car restraint use in Australia, as well as one of the world’s most rigorous child restraint standards, RACV training manager Peter Smith, who is also an accredited child restraint installer, says car seats still play an important role in keeping children safe on the road.

Choosing an appropriate baby or child car seat is one of the most important safety decisions you will make,” he says. “But even more paramount is ensuring it is properly fitted and used.”

From incorrect installation to allowing an early transition to adult seatbelt use, Peter says these are the most common car seat mistakes you’re probably making, and how to avoid them in the future. 

Common child car seat mistakes

Not using the right seat for your child  

Before you can install or use a car seat correctly, you need to make sure the seat is appropriate for your child’s age, size, meets road safety laws, and that it complies with Australian Standards.

Child car seats and modes are designed to be used at different ages, but Smith says height is a more accurate measure of whether a child is ready to move into the next type of seat. “Choosing the right restraint depends on the age and size of your child,” he says. “Not all four-year-olds are the same height so age should be used as a guide only.”

Child car seats have a shoulder height marker that dictates when a child is ready to move into the next mode. The following can be used as a guide, but always refer to the manufacturer’s instructions on which seat to use.

  • Capsule/rear-facing: Birth to six months (some can be used to at least 12 months, others for up to 2.5 years). It is recommended to keep children in rear-facing mode until they are too big for it.  
  • Forward-facing: Six months to at least four years old, or until they have outgrown it.
  • Booster: Four to seven years old, with some made for children up to at least 10 years.

Seat doesn’t meet Australian standards

If you’re buying a child restraint second-hand, it’s important to do your homework. “RACV market research found that 1 in 5 second-hand child restraints sold online or in-store weren’t suitable for sale because they were damaged, too old, or an illegal overseas model,” Smith says. “Always make sure the restraint is in good condition, hasn’t been in a crash, and is less than 10 years old for the entire time you will need to use it.” 

Try to buy a new seat if you can. Every restraint on the market with an Australian standards sticker has passed minimum safety requirements. 

If you’re considering a used car seat, Smith says to make sure you know the seat’s history and to only buy a restraint that meets the Australian Standard. These are his top tips for buying a second-hand child car seat:

  • Check the year of manufacture and model number and don't buy a restraint that's more than 10 years old. A sticker will show the date of manufacture. Don’t buy a seat that doesn’t have the date stamp. 
  • Check that there is no wear and tear, no missing parts and that the buckle clicks into place securely.
  • Ask the owner if the restraint has ever been in a crash. Damage isn’t always obvious and a restraint that's been in a crash must be destroyed and should not be sold.
  • Ask for the instruction manual or find it online so you can find out how to use the restraint correctly.
  • Check that the seat hasn’t been recalled.
Woman securing baby into rear-facing child car seat

Keep your seat in rearward-facing mode for as long as possible. Photo: Getty. 

Seat is not fitted correctly

Fitting a child restraint can be harder than you think. In fact, Smith says more than 70 per cent of child car seats aren’t installed correctly – which can lead to serious injury or death in a crash. 

Some of the biggest mistakes people make when installing their seat include reclining the seat at the wrong angle, not using the tether strap, not checking that the seatbelt or ISOFIX connectors are properly secured and not making sure the harness and seatbelt are firm and untwisted. “Child restraints and most booster seats need to be attached via a top tether strap to an anchor point in the car,” he explains. For the location of anchor points in your vehicle, refer to your owner's manual and be careful not to confuse a luggage hook with an anchor point.

RACV has a network of restraint fitters throughout Victoria who can fit your restraint or check that it’s installed correctly.”

Seat is too loose in the car

If you can move the seat from side to side or back and forth when holding it at the base, it might be too loose. This could put your child at increased risk of crashing into the seat in front in the unfortunate event that you are in a collision.  “This is one of the biggest mistakes parents make,” Smith says. “If yours is wobbly, fix it by making it a habit to check and tighten straps every time you get into the car.”

You’re using the seat in the wrong mode

Buying and fitting a car seat is only part of keeping kids safe; using the seat correctly in each mode is also imperative. “Babies are safer if they stay in their rearward-facing restraint for as long as possible,” Smith says. “But be mindful to always recline the car seat according to the manufacturer's instructions.”

Babies’ airways are very narrow and, if the seat leans too far forward, their heads might not be supported properly and can fall forward. 

“Only use a forward-facing restraint once your child is too big for the rearward-facing mode.”  

Harness is too loose on your child

Making sure the harness is ‘pinch test tight’ is essential to ensuring your child is safe when travelling.

“If you can pinch the straps near your child’s shoulder, the harness is too loose,” Smith says. “This could increase their chances of injury should you brake suddenly or get into a crash.”

Keep your child, safe, secure and snug in the harness by ensuring there is no slack on the straps.

Make it a daily habit to loosen the harness strap when you get your child out of the car and tighten it again when you’re buckling them in. 

Using a chest clip

Though chest clips are used widely in the US, they are not recommended for use in Australia. “Chest clips are designed to keep the shoulder straps together to prevent children from wriggling their arms out of the harness,” Smith says. “They are available to buy in Australia but should only be used as a temporary last resort if your child is freeing themselves. Using a chest clip can also make it harder to remove a child from a car if there is a crash so avoid using one unless it is absolutely necessary and behavioural solutions have not worked.”


Young boy strapped into car seat playing with toy in window

Your child should be 145cm tall before moving to an adult seatbelt. Photo: Getty.

Not using a booster seat correctly

Booster seats must be used with a seatbelt only once a child no longer fits into their forward-facing restraint. (You can check this by seeing if your child’s shoulders fit below the maximum shoulder-height marker line on the restraint.)

There are two types of booster seats. Single-purpose booster seats, which have side and head protection, are designed to be used with a lap/sash seatbelt and usually have a top tether. Forward-facing car seats that convert to a booster can be used as a forward-facing restraint with a harness until at least age four, then as a booster with a lap/sash belt.

“It’s safest for children to use a booster seat until they outgrow it otherwise, they may not achieve a good seatbelt fit,” Smith says. “Some booster seats suit older children until around 10 years of age.”

Using a booster cushion 

Booster cushions were removed from the 2010 Australian Child Restraint Standard. They are no longer manufactured but may still be available to buy second-hand.

“Booster cushions might seem like a convenient solution, but they don’t offer side or head protection in a crash, so they’re unsafe to use and are not recommended,” Smith says. 

Child graduates to an adult seatbelt too soon

The law requires children aged seven to 16 years to use a properly fastened and adjusted booster seat or seatbelt; whichever is most suitable. “Your child must continue travelling in a booster seat until they can pass the five-step test, which is usually when they are 145cm tall,” Smith says.  

Your child is ready to move into an adult seatbelt if:

  • Their back is flat against the seat 
  • Their knees bend comfortably at the edge of the seat
  • The seatbelt sits across the shoulder properly between their neck and arm 
  • The lap belt sits low across the hips and touches their thighs
  • They can stay seated comfortably without slumping for the whole trip 
  • They are at least 145cm tall

Not checking and adjusting the seat every time you put your child in

You adjust your own seatbelt whenever you buckle up in the car so why wouldn’t you adjust your child’s? “Even after a seat has been properly installed, it’s important to regularly check it and make adjustments as children grow,” Smith says. “Straps can loosen over time, harnesses can need adjusting depending on what children are wearing, or your child might have had a growth spurt!” 

You’re not checking the safety rating

When it comes to baby and child car seats, not all restraints are created equal. “Price doesn't necessarily reflect how safe a car seat is,” Smith says. “The Child Restraint Evaluation Program (CREP) assesses the protection rating of car seats above Australian Standard requirements and provides information on ease of use.” Check out our guide to the safest child car seats for 2022. 


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