Untethered booster seats are a replacement for bum boosters, which became illegal to sell with the introduction of the 2013 Australian Standard. Here’s where and when you should actually use an untethered booster seat.
🪑 What is an untethered booster seat?
The untethered booster is a lightweight seat designed for occasional use, and for situations where there are no anchor points installed — such as the third row of a seven-seater SUV or van.
“Occasional use” covers situations like a grandparent picking up a grandchild from childcare sometimes, or needing to collect children in an emergency.
⚠️ Booster cushions
Booster cushions (polystyrene booster seats) are no longer sold in retail stores, and offer no side impact protection. New booster cushions — potentially sourced from overseas — can be dangerous and have not passed the Australian Standards.
✕ This type of booster no longer complies with current standards, is no longer manufactured, and is illegal to use.
✕ Booster cushions offer no side impact protection, and even where legacy use might apply, must only be used in the centre position of the back seat.
📏 Height markers
Like all booster seats, an untethered booster has a minimum shoulder height marker and a maximum shoulder height marker. Even if your child is over 4 years old, if they haven’t reached the minimum shoulder height marker, using the untethered booster is dangerous.
All untethered boosters need to offer back and side protection, and weigh under 2kg.
Height markers for untethered booster seats (4–8yrs)
| Seat | Entry | Exit |
|---|---|---|
| Safe n Sound Tourer | 38cm | 50cm |
| Safe n Sound Urban | 35cm | 49cm |
| Hipod Rio | 40cm | 48cm |
| Infa Secure Versatile/Traveller | 36cm | 45cm |
| Babylove EzyMove | Not published in our source data | |
⚖️ Untethered or tethered?
It’s always preferable to use a tethered booster seat, as it provides additional security — an adjustable headrest, a sash guide for the seat belt, and (on Britax seats) an anti-submarining clip to stop your child sliding under the seat belt. Given the number of adjustments on the Britax Hi-Liner, it’s recommended to call a mobile baby car seat installer to teach you how to make the necessary adjustments.
✅ Recommended untethered booster seat
If you have the choice between a tethered or untethered booster seat, always choose the tethered option. Wherever possible, use a booster seat with a high back and sides.
The only untethered booster seat we can recommend is the Britax Tourer, which has an anti-submarining clip to prevent sliding under the lap section of the seat belt. Note: our source also lists a “Safe n Sound Tourer” in the height marker table above — Safe n Sound is a Britax-owned brand in Australia, so this is very likely the same seat under two names used inconsistently. Worth confirming and standardising to one name before publishing.
❓ Frequently asked questions
What is an untethered booster seat? ＋
Are booster cushions (bum boosters) still legal? ＋
What safety requirements apply to untethered boosters? ＋
Should I choose a tethered or untethered booster? ＋
Which untethered booster seat is recommended? ＋
When would I actually need an untethered booster? ＋
Bayside Baby Car Seat Installation
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