Car Seat Safety: 5 Installation Mistakes

According to the Irish Road Safety Authority, 3 out of 4 car seats are fitted incorrectly. A scary thought for the most important piece of safety equipment you will buy for your child. Car seat safety is top of the agenda at The Stork Exchange and over the years, we’ve seen the same mistakes repeated over and over. We’ve listed the top 5 most common installation mistakes people make, and how to remedy them.

Mistake #1: If the Car Seat is Installed too Loosely…

…. and you can wiggle the seat more than an inch forward, or from side to side, you haven’t pulled enough slack off the seat belt. This means that in an accident the seat can crash into the back of the front seat causing serious injuries to the head and face.

Fast fix: This is easy enough to resolve, and we find two adults are better than one in this situation. When installing a seat, place a knee into the seat (if it’s forward facing) or an arm across an infant seat and press the seat down with all your weight. The second adult can then easily pull the slack off the belt, tightening it as much as possible, making sure the belt isn’t twisted, then lock off the belt lock on the car seat.

Mistake #2: Threading the Seatbelt through Both Shoulder Guides….

…. Is incorrect. Despite the fact there are belt guides on both guides, the shoulder seat-belt strap should only thread through on one side – the opposite side to the buckle.

Fast Fix: Thread the shoulder strap through the shoulder guide (2) on one side only and run it diagonally down to meet the waist strap and follow the guides to clip it into the buckle.


Installing a forward facing seat correctly.
Car Seat Safety

Mistake #3: The Harness is Too Loose.

…Parents often worry the straps are too tight and “dig” into the child’s shoulders but it’s very important that the harness straps are pulled tight, preferably without a puffy coat on.

Fast Fix: Try the pinch test – if, after you’ve tightened your child into his car seat, you can still pinch the fabric of the harness straps between your fingers, the harness is too loose.

Mistake # 4: Moving up a Car Seat Stage too Soon…

This is a dangerous mistake to make. …. the trick here is to remember it goes by weight AND height. The risk behind turning an infant around too soon, or moving a child from a forward facing Stage 1 seat to a booster too early, are frightening.  Warning: skip to the next point if you don’t want to know the dangers.


The bones that protect an infant’s spinal cord are still forming. When a child is rear-facing, his back–the strongest part of his body–can better absorb the immense forces of a crash. Facing forward, an infant’s relatively heavy head can catapult forward, causing his underdeveloped spine to expose his spinal cord and putting him at risk of paralysis or death.


Similarly, any child between 15kgs and 36 kgs (40 lbs and 80 lbs) and up to 4’9″ tall (generally, kids from 4 to 8 years old) needs to move into a highback booster seat. The reason being, that an adult seat belt used by itself doesn’t properly restrain a child: it crosses her body at the wrong spots: high up on her tummy, high up across her shoulder, and sometimes even across the neck. Children often move the shoulder belt behind them because it’s uncomfortable. In a crash, a child who’s too small for a seat belt can sustain massive internal-organ damage or head and spinal injuries, and can even be ejected.

Fast Fix: Keep your child in the appropriate seat until they reach both weight and height guidelines.

Mistake #5: Harness Straps Threaded through the Wrong Slots

We see this a lot –  parents don’t adjust the harness slots properly as the child grows up through the seat. Or sometimes the strap feeds through the car seat cover at the correct slot, but then jumps up/down to feed through the slot in the back of the car seat. Most child seats are designed with three / four sets of harness slots: The lower two sets are for the rear-facing position, and the top set is for the forward-facing position. On most seats, once the seat faces forward, only the uppermost slots have the extra reinforcement necessary to keep the harness secure in a collision.

The danger: When the child faces forward, a harness in the lower slots can break through the seat during a collision.

Fast fix: Always check the instructions or ask an expert to find out which slots are for what. As a quick check – make sure the harness straps sit on or slightly above the child’s shoulders in a forward facing seat.

3 thoughts on “Car Seat Safety: 5 Installation Mistakes

  1. This is a splendid post! A car seat is [worth investing in] since they are in them to such an extent! I have absolutely never purchased one that was [cheap].my favorite is Jessica King Best Infant Car Seats but after I tried [alot] of them. My little girl is for all intents and purposes 2 and has the Diono Radian and I am happy to say that we LOVE it! […]

  2. Yes, three “or”‘s and no “and” in the guideline. Also, should the child be age 1 or 2? You mentioned age 2 and 20lbs a lot and then the childs first birthday… 20lbs is about what a one year old should weigh… so you probably ment age 1 and 20lbs right?

    1. Hi Molly, thanks for the comments – sorry, but I don’t understand what you mean by the first part? The age of the child really is not the guiding factor when choosing a car seat, it should be weight and height… Yes you are correct a 1 year old weighs roughly 20lbs, but I can’t see where I said age 2 and 20lbs in the post, could you let me know so I can edit it?
      Thanks a million:)


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