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Baby & child.

Updated: 28 Mar 2022

Baby and child car seat accessories: what's safe?

We investigate a range of baby and child car seat accessories to see if they're safe, including the 5 Point Plus Anti Escape System, Buckle-upp buckle guards, neck pillows and more
Hannah Fox
Snoozeshade for car seat

There are numerous child car seat accessories available to buy from the major baby retailers and online.

They’re designed to solve a range of different issues you might encounter while your child is sat in his or her car seat including:

  • your child unbuckling him or herself while the car is moving
  • your child’s head or body flopping forwards or to the side while sleeping
  • the geometry of the vehicle’s seatbelt not matching up with the car seat, making it difficult to buckle up your child
  • your child feeling too hot or cold while in the car.

However, we'd strongly advise you to be careful what you go for. Car seats are crash-tested in the way they are designed to be used, and adding accessories such as chest clips or seat covers that aren't approved by the manufacturer could compromise the seat's safety and/or void the warranty.

See our child car seat reviews.

child escaping from harness

Are child car seat accessories safe?

We got expert viewpoints from our car seat testing team on whether the enormous range of accessories available are safe or appropriate to use.

5 Point Plus Anti-Escape system

5 point plus anti escape system

The 5 Point Plus Anti Escape System has been on the market for some years now. But since the beginning of 2016, it has come integrated into all Cosatto's Group 1 and 1/2/3 car seats, so the brand clearly agrees with its benefits.

It's a fabric harness that fits over the five-point harness of the child seat, reducing the size of the arm holes to make it much harder for arms to slip out of shoulder straps.

We crash-tested the 5 Point Plus and our experts didn’t see any negative effects on the dummy loads (that's what our tests use to replicate a child being in the seat). It also doesn’t prevent parents from unclicking the harness in one action to get their child out of the car quickly.

Verdict: Safe to use

Chest clips

car seat chest clips

This is a plastic clip that’s attached to the integral harness to hold the straps together, ideally at chest height. It’s designed to stop your child slipping their arms out of the harness.

However, as most child car seat harnesses come with padded shoulder pads that cover the straps, you may find you need to mount the clip quite low, so it sits across the stomach and not the chest.

Our car seat testing experts were concerned that this could potentially increase dangerous amounts of pressure on the soft area of your child’s abdomen in the event of a crash.

What’s more, if you own a car seat that claims to comply to the R44 car seat regulations, using a chest clip could mean you’re breaking the law. That’s because the regulation states that you should be able to release the child from the harness restraint in one operation. Adding an extra chest clip means you have to open two buckles. If you have an R129 car seat, chest clips are permitted.

Verdict: Not recommended unless you own a car seat that meets R129 regulations – check the label

Seatbelt buckle blocks

child seat seat belt lock

This is a plastic guard that's placed over the vehicle’s main seatbelt buckle, and then the belt is clicked into it. It’s designed to stop children pressing the buckle button while you’re driving, and is marketed at any children who are strapped into their car seat using the adult seatbelt (such as with a group II/III car seat). Brands available in the UK include BuckleSafe! and Roadtrip Essentials BuckleUp Belt Lock Buckle Guard.

In order for a parent to release the device, you need a separate key (or your own car key) to slot into a narrow opening to activate the main seatbelt button and release the buckle.

Regulations on the use of adult seatbelts state that the buckle should be easy to use and capable of being released by the wearer in a single movement. This is so that, in the event of a crash, it will speed up the rescue and removal of occupants from the car. However, with the buckle guard in place, these devices require you to either locate the included plastic key or remove your own car key from the ignition to activate the release button. This slows down the removal time and means the seatbelt buckle no longer meets the legal requirements.

Most modern cars have a warning system that will alert the driver if anyone sat in the back does not have their seatbelt attached, so we feel that this is a good way of keeping an eye on the status of seatbelts in the back of the car. While it can be frustrating to have to stop regularly to buckle your child back in, we can’t recommend these devices if it means your car seat is not meeting the legal requirements for use.

Verdict: Not recommended

A spokesperson for Roadtrip Essentials BuckleUp Belt Lock Buckle Guard told us: ‘We will look into this in more detail and if necessary redesign the product. Our intent is to help people move from A to B in the safest way.’

We contacted BuckleSafe! for a comment but were unable to reach anyone.

Buckle-upp Anti Escape System

car seat buckle cover

The Buckle-upp Anti Escape System is a cushioned mesh cover that attaches to the car seat harness buckle and covers the release button. It’s designed to prevent unbuckling when travelling.

Both R44 and R129 car seat regulations state that buckle restraints should be released during a single operation, which this cover will prevent you from doing. This means using the Buckle-upp will mean your car seat does not comply with legal regulations.

Verdict: Not recommended

Buckle-upp told us that the attachment does not have an adverse effect on the safety of the seatbelt itself but is instead a safe option for parents who want to ensure their child remains in an upright position.

Neck pillows

neck pillow

These are designed to prevent your child’s head from flopping forward when asleep. They usually sit around the neck and across the shoulders, but aren’t attached to the car seat, and our car seat experts have confirmed that they do not conflict with the R44 and R129 car seat regulations.

Just make sure that you select a pillow that properly fits your child so that it is comfortable.

Verdict: Safe to use

NapUp head supports

Nap up head supports

The NapUp is a head support that’s equipped with two straps to connect it to the car seat backrest. It comes with a head support band that can be folded down for additional support when the child has fallen asleep preventing the head from flopping forward.

Not every child will be happy having their head strapped to the seat in this position. However, the use of the NapUp does not conflict with the requirements of regulations R44 or R129.

Our car seat experts carried out a crash test using the NapUp. During the crash, the head support band, which uses push buttons for attachment, comes off. This means it won’t interfere with the protection of the car seat itself.

Verdict: Safe to use


BeltUpp safety belt for child car seat

The BeltUpp is an additional safety belt for high-backed booster seats. It’s attached to the lap and shoulder straps of the vehicle seatbelt and inserted in the respective guides on the booster seat.

With the BeltUpp installed, your child will have an ‘X’ pattern across its chest. It’s designed to provide better support for a sleeping child and to stop them from slipping out of the seatbelt.

However, strapping in your child with an additional belt means you’ll have to release a second buckle, and you won’t be able to release your child in one action (a requirement of both R44 and R129 car seat regulations).

Verdict: Not recommended

A spokesperson for BeltUpp told us: ‘BeltUpp has an extra buckle to undo but it is in fact quicker and easier to get a child out from this system than it is when they have a harness and a centrally placed buckle. The additional buckle is the first thing you see when you open the car door so there is no confusion as to how to undo it. Senior Trading Standards and Senior Fire Brigade officers have looked at BeltUpp in detail and state that there is nothing to substantiate any suggestion that the device is unsafe.’

Smart Kid belt

This is a belt guide consisting of two red clips and a piece of belt. It's designed to be used with children aged four to 12 years. The idea is that you clip it to the adult seatbelt to pull it down and up so that it sits across the correct parts of your child's body. It's designed to remove the need for a high-backed or backless booster seat, as it ensures the adult seatbelt sits across the correct parts of a child's body to provide protection without applying too much pressure.

This product was approved to R44 regulations. However, when we carried out our own crash testing with it, we discovered that the product doesn't keep the shoulder part of the vehicle seatbelt low enough in a frontal collision. The horizontal belt also pulls up during a crash, meaning the seatbelt will pull across your child's delicate abdomen and potentially cause dangerous internal injuries. We believe that using the Smart Kid Belt would be no safer than transporting your child using just the vehicle seatbelts, something that is prohibited for children who are less than 1.35 metres.

Verdict: Not recommended

The manufacturer of the Smart Kid Belt told us it thinks it's being unfairly targeted by market competitors. The company says it's had the Smart Kid Belt independently tested to the relevant Standard, and the results prove that the Smart Kid Belt is safe and effective.

Seatbelt triangle pad

car seat seat belt triangle pad

The seatbelt triangle pad is designed to pull the cross-body part of the adult seatbelt away from your child’s neck, and provide additional padding.

But our car seat experts noted that if the pad is poorly placed, it could pull the lap belt up and the shoulder belt down, so that they run across the sensitive abdomen area, which could be dangerous in a crash.

A good high-backed booster seat should be able to guide the seatbelt into the right positions so it sits comfortably across your child (and it’s one of the things we check in our car seat testing), so a triangle pad is redundant if you have a decent car seat.

Verdict: Not recommended

Seat Belt Buckle Extension Extender Clip

seat belt buckle extender clip for car seat

This is a second buckle that's clicked into your vehicle's main seatbelt clip. It’s designed to make it easier to buckle up your child by raising the position of the buckle, making it more accessible.

But to comply with requirements set out in EU car seatbelt regulations, the distance between the belt guide at the vehicle seatbelt tongue and the edge of the backrest bottom/seat surface should not exceed 150mm. This buckle means it will exceed that distance.

Also, doing this means the location of the buckle will sit next to the hard plastic part of the car seat, and could cause something called ‘buckle crunch’ where pressure is put on the buckle and subjects it to bending movements, which could weaken it.

Verdict: Not recommended


RiveMove car seat mount

This is a device that’s mounted to the in-car Isofix anchor points to help you position your car seat so it’s closer to the car window, and it will allow more room in the central seat if needed. The manufacturer recommends only using it with group II/III car seats.

Our car seat experts were concerned that installing a RiveMove may change the load distribution between the Isofix points, meaning they may no longer withstand a crash.

However, they confirmed that this is not too much of an issue if your child is strapped into their car seat using the car’s adult seatbelt, as that will absorb most of the impact. But it does mean that you shouldn’t use this device if your car seat is only installed via the Isofix points and your child is strapped in using a harness.

Verdict: Only recommended with group II/III booster seats

A spokesperson for RiveMove told us: 'Before launching our product into the market we carried out numerous tests in CSI Spa (Italy) in accordance with regulations ECE R129, with which groups II/III car seats are homologated, demonstrating its safety. After analysing the results of these tests experts have expressed their confidence with our accessory.'

Summer car seat cover

Summer car seat cover

Some manufacturers make interchangeable car seat covers for their products. For example, summer covers are designed to be cooler for your baby or child in the hotter months.

R44 and R129 both make it mandatory for a rear-facing child car seat to carry a visible airbag warning label on the inner surface of the seat, near where the head sits. 

Car seat labelling should be clear and not obscured

If the car seat cover does not have this, then technically it will mean the car seat is not meeting all the legal requirements.

Verdict: Only recommended if it does not cover warning labels when used on a rear-facing seat

Winter footmuff

A footmuff is designed to keep your child warm and cosy, and has holes for the (3-point or 5-point) harness and the buckle to secure them.

It’s a good alternative to thick winter clothes, which make buckling in your child difficult and can potentially diminish the restraining effect of the harness due to belt slack. However, it should only be used in an infant car seat as the whole carrier can be removed with the child in it in the event of a crash.

You should not use a footmuff with any other type of car seat, as it will cover the harness buckle and prevent an easy release of the buckle after a crash.

Verdict: Only with an infant car seat

Car seat blankets

These are blankets or swaddles that have harness holes cut out, so you can wrap them round your baby and still buckle them in. Unless they are recommended by the manufacturer of your car seat, we think you should steer clear.

Even with blankets that are recommended, be very careful that the harness is tightly done up.

This is for the same reason that you shouldn’t dress your child in bulky winter coats. Although you may feel that you’ve done the harness up tightly, the soft padding of a coat will compress in an accident.

As a result, the harness straps will be looser than they should be, which could expose your child to higher forces in a crash. If you are worried about your child being cold in the car, dress them in several thin layers.

Verdict: Not recommended

Window sunshades

Infant car seats tend to have built-in sunshades, which are not only useful for keeping the sun out, but also provide a layer of protection from flying glass if you're in an accident.

If you want sunshades, try to choose ones made by car seat manufacturers, as they should have had some level of crash testing.  

Make sure any you choose are securely attached, especially as the suction pads could fall off or be pulled off by small children and become a choking hazard. 

Verdict: Safe to use

Car seat protector

Car seat protector

A car seat protector may seem like a good idea. They're designed to protect your back seat from dents or scratches that could potentially be caused by your child car seat, but in reality they could compromise the safety of the car seat.

Additional padding or material between the seat and its fixing could mean the seat is not as firmly fitted as it should be, which could have serious consequences in a crash. 

Even if the protector is claimed to have been crash-tested, it certainly won’t have been tested with every car seat. 

If a manufacturer sells one to go with its car seat, it should have been crash-tested with it. But if it's a generic cover we'd recommend contacting the manufacturer to make sure it's approved for use with your car seat, or it could invalidate the seat’s warranty.

Verdict: Only recommended if the cover has been crash-tested with your seat


car seat mirror

When your child is in a rear-facing car seat, you can’t see them when you're driving. So it’s understandable that many new parents buy mirrors that attach to the back seat's headrest to get a view of their baby from the rear-view mirror.

These mirrors are popular, but many safety experts feel they are a distraction, and we wouldn't recommend using them.

This is because trying to make eye contact with your little one, or see what he or she is up to while you're at the wheel, stops you concentrating on your driving. 

Also, in an accident, there's a real danger that the forces of a crash would cause the mirror to come loose and hit someone.

Verdict: Not recommended


Some manufacturers make cup-holders that clip on to the side of the seat, and some seats have cup-holders built in.

It's useful to have a secure place for a child’s drink to go so that he or she can reach it, to save you pulling over or engaging in dangerous driving while trying to retrieve the bottle. We would advise using one recommended by the manufacturer.

Of course, a cup in the car could fly free in an accident and a cup-holder may not prevent this, so bear this in mind.

Verdict: Use one recommended by your car seat manufacturer

To see a selection of car seats that we recommend, visit our round-up of the best car seats.

What do car seat manufacturers say?

We asked Britax, one of the leading car seat manufacturers, for its view on seat accessories. A spokesperson said: 'We invest significant time in the research, development and testing of our own manufactured accessories which accompany our child car seats. This ensures that the accessories offered enhance the consumer experience by offering added comfort and practicality, but doesn’t interfere with the crash performance of the car seats.

'Furthermore, the warranty of our car seats will be invalid if an accessory not developed by us is used in conjunction with the seat, ie a permanent attachment to the seat. This is because any accessory attached to a car seat would require homologation to ensure the seat still performs in a crash as it should. Therefore we would advise against using accessories not developed and tested by the car seat manufacturers. On the other hand, an accessory which is not attached to our car seats won’t affect the warranty as it won’t have an impact on restraint performance during a crash.'

We also contacted Cybex. A spokesperson stated that it follows the same advice provided by the Baby Products Association: 'Only products supplied or recommended by the car seat manufacturer should be used with the car seat. The use of a non-approved accessory could invalidate your insurance. There are products available that reduce this problem. Speak to the manufacturer if you are not clear which products they recommend.'

What do the car insurers say?

We also asked different insurance companies whether using car seat accessories might affect your chances of putting through a claim for a damaged car seat in the event of a crash. This is what some of them said.

M&S Bank

'The use of child car seat accessories wouldn’t affect child seat cover, or invalidate the vehicle insurance in the event of a claim. However, the cost of the accessory itself wouldn’t be covered as it doesn’t form part of the original car seat.'


'It’s unlikely we would reject a claim based on car-seat accessories alone. That said, we would encourage parents to ensure their car seats are fitted properly to reduce the risk of injury.'

NFU Mutual

'We cover car seats under ‘Spare parts and Accessories’ for damage. While the accessories would not necessarily invalidate cover, we would always urge drivers to act responsibly and to put safety first.

'In some cases the use of accessories could be a source of contributory negligence if for instance, the driver becomes distracted and causes a collision, or if loose pieces obstruct the use of controls. Any resulting police penalty could have an impact on premium or the driver’s ability to renew.'


'We haven’t yet seen any issues with car seat accessories causing problems at claim stage and therefore cannot envisage a scenario where a claim would not be covered.'

Finding the right car insurance policy can be tricky and, at times, overwhelming. Discover useful tips in our car insurance advice guides.