Every parent wants their little one to be as safe as possible in the car—but the reality is, car seats can be confusing. Even when you’ve read the manual, watched the install videos, and double-checked your work, it’s easy to miss small details that make a big difference in safety. In fact, studies show that nearly three out of four car seats are used incorrectly in some way.
The good news? Most mistakes are quick fixes once you know what to look for. Below, we’ll walk through 18 of the most common car seat safety mistakes parents make and share straightforward tips to help you avoid them (so your little one is as protected as possible on every ride).
Your Car Seat Installation Is Too Loose
How to check: A properly installed car seat should pass the “inch test.” Once it’s secured, give it a firm tug right at the belt path (where the seat belt or LATCH strap threads through the shell or base). It shouldn’t move more than an inch side-to-side or front-to-back at that spot. If there’s more wiggle further away from the belt path, don’t worry, that’s normal.
The potential danger: A loose install might not seem like a big deal, but in a crash that extra slack means the seat can lurch forward, putting more strain on your child’s head and neck. Even a little movement can reduce how well the seat does its job.
How to fix it: Start by pulling out your car seat manual and your vehicle manual—they’re the real MVPs here. Every car seat must be installed with either the seat belt or the LATCH system (never both). Remember that LATCH has a combined weight limit (usually 65 pounds for seat + child). The middle of the back seat is often the safest spot, but if you can’t get a solid install there—or if your car doesn’t allow it—the sides are fine too.
And yes, installation usually takes some muscle. Even “easy install” seats benefit from a little extra effort. Press the seat base firmly into the vehicle seat and lean in with your body weight (a knee works great) while tightening the belt or LATCH strap. Rock it gently side to side as you pull out the slack, and if you’re using the seat belt, make sure it’s locked once you’re done.
With almost half of seats installed incorrectly (per the NHTSA), it’s smart to have your work checked by a certified Child Passenger Safety Technician (CPST). Many police and fire stations have CPSTs on staff, or you can search by zip code at seatcheck.org.
You’re Forward-Facing Too Soon
How to check: Both the American Academy of Pediatrics (AAP) and the National Highway Traffic Safety Administration (NHTSA) recommend keeping kids rear-facing for as long as possible—until they reach the maximum height or weight allowed by their specific seat. (Check the label or manual for your model.) The AAP used to say rear-facing until age two, but their 2018 update made it clear: stay rear-facing beyond that milestone if your seat allows it.
The potential danger: In a front-end crash, everything in the car surges forward. Adults are held back by the seat belt, but the head still whips forward before stopping—that’s whiplash. For toddlers, the risk is much greater. Their heads are proportionally larger and their spines are still developing, which makes forward-facing too soon especially dangerous. The force on the neck and spinal cord can lead to severe injuries that rear-facing would help prevent.
How to fix it: Keep your little one rear-facing until they outgrow the limits of their car seat. Yes, their legs might look a little scrunched as they get taller, but that’s completely safe. Kids are naturally flexible, and crossing their legs or resting their feet on the seat back isn’t a problem.
Your Rear-Facing Car Seat Is at the Wrong Angle
How to check: Every rear-facing car seat comes with some kind of recline indicator—maybe a bubble level, a color-coded line, or a simple graphic printed on the side. Use it! The goal is to make sure your baby’s head rests comfortably against the seatback, not tipping forward. And if you’re not sure, double-check your car seat manual for specifics.
The potential danger: This isn’t just about comfort. If the seat is too upright, a young infant’s head can slump forward and press against their chest, which can block their airway. Newborns and preemies are especially vulnerable because they don’t yet have the neck strength to keep their head in a safe position.
How to fix it: Adjust the recline so it matches your child’s age and stage—infants need a deeper recline, while older babies can ride more upright. Many seats have built-in recline settings or wedges to help with the angle. Some parents worry that a more reclined angle makes the seat less secure in a crash, but if you’re following the seat’s indicators, you’re giving your baby the best of both worlds: airway protection and crash protection.
Your Harness Is Too Loose
How to check: The quickest way to know if the harness is snug enough is the “Pinch Test.” Once your kiddo is buckled in, try pinching the strap at their collarbone. If you can grab any slack between your fingers, it’s too loose. A correctly tightened harness should lie flat and snug against their body.
The potential danger: A loose harness means extra movement in a crash, which can allow your child to slide forward—or, in severe cases, slip out altogether. Even a little bit of slack can reduce how well the seat does its job. Parents sometimes hesitate to tighten too much, worrying about comfort, but here’s the truth: a properly snug harness is what keeps your little one riding safe.
How to fix it: Each time you buckle in, tighten the harness until it passes the pinch test. The straps should feel like a firm hug; not digging in, but definitely not loose. As long as your child can breathe easily and move their arms, you’re in the safe zone. That extra few seconds to snug things up is what ensures the harness can actually protect them.
Your Harness Chest Clip Is in the Wrong Place
How to check: The chest clip should sit at armpit level—that’s the spot the keeps the harness snug across your child’s shoulders. Slide it up or down until it lines up with their underarms. It may look like a small detail, but that placement makes a big difference in how the harness works.
The potential danger: If the chest clip is too low, the harness can slip off your child’s shoulders in a crash. If it’s too high, it can press into the neck and cause injuries during a sudden stop. Some parents assume the clip is mainly for comfort, but its real job is positioning. When it’s out of place, the harness can’t do what it’s designed to do.
How to fix it: Once your child is buckled, take a quick second to adjust the chest clip to armpit level before hitting the road.
Your Shoulder Straps Aren’t Positioned Correctly
How to check: Strap height depends on how your little one is riding. For rear-facing, the harness straps should be at or just below the shoulders. For forward-facing, they should be at or just above the shoulders. This positioning helps the harness hold your child securely in the seat during a crash.
The potential danger: If the straps are too high when rear-facing—or too low when forward-facing—your little one has extra room to move in the harness. That extra slack means more forward motion in a crash, which increases the forces on their neck and spine. Even a small misalignment can affect how well the seat protects them.
How to fix it: Check strap height regularly, especially during growth spurts. Adjust the straps so they line up with your kiddo’s shoulders depending on their orientation, and make sure the harness lies flat without twists. It’s not an adjustment you’ll make every week, but it’s worth revisiting as your child grows.
You’re Not Using the Top Tether
How to check: Forward-facing car seats come with a top tether strap, a piece of webbing that extends from the back of the seat and hooks onto an anchor point in your vehicle. It’s easy to miss since it’s often tucked away when the seat is new, but it should always be attached when the seat is forward-facing.
The potential danger: Without the tether, your child’s head can pitch forward up to six extra inches in a crash. That small distance matters—it can be the difference between staying safely contained or striking the seat in front of them. Some parents assume the tether is optional because the seat feels secure with just the lower anchors or seat belt, but it’s an essential part of the system.
How to fix it: Locate the tether anchor in your car (your vehicle manual will show you where it is) and clip the strap in place every time you install a forward-facing seat. Pull the strap snug so there’s no slack. It takes only a few seconds, but it significantly reduces the risk of head and neck injuries in a crash.
You Didn’t Remove Your Child’s Bulky Coat
How to check: Puffy coats, snowsuits, and even thick sweatshirts can make the harness look snug, but the extra padding creates a false fit. If the straps pass the pinch test only because of the coat’s fluff, they’re not actually tight against your child’s body.
The potential danger: In a crash, that padding compresses instantly, leaving slack in the harness. That looseness can let your child slide forward—or even out—of the seat. Many parents worry their child will be too cold without a coat in winter, but warmth can be added safely after the harness is buckled, not underneath it.
How to fix it: Dress your child in thin, warm layers and buckle them in first. Then add warmth on top: tuck in a blanket, drape their coat over them like a blanket, or use a car seat–approved cover or pod. This way, your kiddo stays cozy without compromising harness safety.
You’re Using the Wrong Car Seat for Your Child’s Size or Stage
How to check: Every car seat is designed with specific height, weight, and developmental limits—they’re not one-size-fits-all. The right seat should fit where your child is right now, not just what feels easiest or what seems like the next step. That means newborns need a seat that reclines enough to protect their airway, toddlers should stay rear-facing until they max out the limits, and older kids should be in a harness or booster until the seat belt truly fits.
The potential danger: Moving up too soon—or staying in a seat that’s already outgrown—leaves gaps in protection. A baby who’s too small for a convertible may slump forward and struggle to breathe, while a preschooler in a booster too early may not sit still enough for the seat belt to work properly. Safety depends on matching the right seat not just to your child’s size, but also their maturity.
How to fix it: Always check the label on your car seat (or the manual) for the exact weight and height ranges. Transition only when your child has maxed out those limits—not just because of age, convenience, or what their friends are riding in. The right seat at the right stage gives them the best possible protection.
You Stopped Using a Booster Seat Too Soon
How to check: According to the NHTSA, more than a quarter of kids ages 4–7 are moved out of their boosters too early. The best way to know if your child is truly ready is the five-step test:
-
Can they sit all the way back against the vehicle seat?
-
Do their knees bend naturally at the seat’s edge?
-
Does the lap belt sit flat on the tops of their thighs (not their stomach)?
-
Does the shoulder belt rest between their neck and shoulder (not across the neck or arm)?
-
Can they stay in that position for the whole ride without slouching, leaning, or fiddling with the belt?
The potential danger: Without a booster, the seat belt usually doesn’t fit smaller kids correctly. The lap belt can creep up onto the belly, and the shoulder belt can cut across the neck. In a crash, that poor fit raises the risk of serious abdominal or spinal injuries. Many parents assume age alone is the deciding factor, but proper belt fit and maturity matter just as much.
How to fix it: Keep your child in a booster until they can confidently pass all five steps—most kids need one until they’re between 10 and 12 years old. It may feel like a long time, but the booster ensures the seat belt is actually protecting them the way it’s designed to.
You Moved to a Booster Too Soon
How to check: Most convertible car seats let kids stay harnessed until at least 65 pounds forward-facing (and some go higher). The AAP recommends keeping children in a five-point harness as long as they fit within the seat’s limits, since the harness spreads crash forces more evenly than a seat belt alone.
The potential danger: It’s easy to assume that once a child hits preschool or kindergarten, they’re ready for a booster. But most kids under 5 or 6 simply aren’t there yet. They may wiggle, lean, or slip the belt behind their back. And even if they’re technically big enough, that behavior means the seat belt won’t protect them properly in a crash.
How to fix it: Keep your child in a harnessed seat until they truly max out the height or weight limits. When it’s time to switch to a booster, it should be because they’re both big and mature enough to sit still with the belt in place. Think of the harness as training wheels: you don’t take them off until your child is fully ready for the next stage.
You’re Using an Expired Car Seat
How to check: All car seats come with an expiration date—usually somewhere between 6 and 10 years after the manufacture date. You’ll often find it stamped on the underside of the seat, on the base, or in the manual. It’s worth looking for so you know exactly when the clock runs out.
The potential danger: Car seats aren’t built to last forever. Over time, the materials can weaken, safety standards evolve, and older models may no longer meet current crash-test requirements. An expired seat may look fine, but it may not protect your child the way a newer model will.
How to fix it: Double-check the expiration date on any seat you’re using—or thinking about reusing for a younger sibling. If it’s expired, it’s time for a replacement. Expiration dates aren’t just about selling more seats; they’re there to make sure your child’s protection is up to date with the latest safety standards.
You’re Using a Used Car Seat Without Knowing Its History
How to check: Hand-me-downs can be great for a lot of baby gear, but car seats are a different story. Before saying yes to a used seat, you need to know its full history. Has it expired? Been in a crash? Been recalled? Is it still registered with the manufacturer? If you can’t answer all of those with confidence, it’s not worth the risk.
The potential danger: A seat that’s been through a crash or is missing recall fixes may look perfectly fine on the outside, but it may not perform the way it should in an accident. Unlike a stroller or crib, you can’t always see the damage. A “good deal” on a secondhand seat can come at the cost of your little one’s safety.
How to fix it: Reusing a seat you bought new for an older sibling is fine, as long as it hasn’t expired, been in a crash, or been recalled. But if you don’t know the full backstory—like with marketplace finds or distant relatives’ hand-me-downs—it’s safest to pass.
Your Car Seat Has Been Recalled
How to check: Every car seat has a model name, number, and serial number printed on the shell or base. With those details, you can search the NHTSA recall database to see if your seat has been affected. The easiest route? Register your seat with the manufacturer right after purchase, and they’ll notify you directly if a recall ever comes up.
The potential danger: Millions of car seats have been recalled over the years—sometimes for minor issues, sometimes for significant safety concerns. If you don’t know about a recall, you could be strapping your child into a seat that isn’t performing the way it should in a crash.
How to fix it: If your seat is recalled, follow the manufacturer’s instructions right away. In most cases, they’ll send you a repair kit or replacement part at no cost. To avoid missing an important notice, take a few minutes to register your seat. It’s a small step that ensures you’ll always be in the loop.
You’re Using Aftermarket Accessories
How to check: Aftermarket accessories are anything that didn’t come in the box with your car seat—like strap covers, head supports, seat protectors, or inserts you picked up online. Unless the manufacturer specifically approves them in the manual or on their website, assume they haven’t been crash-tested with your seat.
The potential danger: It’s easy to think that if a product is sold “for car seats,” it must be safe. Unfortunately, that’s not the case. Using unapproved add-ons can change how the harness fits or how the seat performs in a crash. Even something as small as an extra pad behind your baby can create slack that puts them at risk.
How to fix it: Stick with what’s included in the box or officially approved by your car seat’s manufacturer. If you want more comfort or protection for your vehicle seats, look for options listed in your manual. It may feel limiting, but the safest setup is always the one that’s been tested to work with your seat as designed.
You’re Misusing Infant Inserts
How to check: Many infant seats (and some convertibles) come with padded inserts or head supports to keep smaller babies snug. These should only be used if they came with your seat and are listed in the manual. If you’ve added a cushy insert you bought separately—or you’re still using the newborn insert past the recommended stage—it’s time for a closer look.
The potential danger: Inserts that weren’t crash-tested with your car seat can interfere with how the harness fits, which changes how the seat protects your baby in an accident. Even the inserts that came with your seat can be unsafe if they’re used longer than the manufacturer allows. A harness that doesn’t sit flush against your baby’s body can leave dangerous slack in a crash.
How to fix it: Check your car seat manual for the exact guidance on inserts—when to use them, and when they should come out. Stick only with what’s included in the box or officially approved by your seat’s manufacturer. It can be tempting to add extra padding for comfort, but the safest setup is always the one the car seat was designed and tested to use.
You Didn’t Replace Your Car Seat After a Crash
How to check: If your car has been in an accident—even a minor one—it’s important to check both your car seat manual and NHTSA guidelines. Many manufacturers say to replace the seat after any crash, while others follow the NHTSA’s “minor crash” criteria. The only way to know for sure is to look up your specific seat.
The potential danger: A car seat can be damaged in ways you can’t see. Even if it looks fine, the crash forces may have weakened the structure, which means it may not protect your child in another collision. A lot of parents assume that if the seat “looks okay,” it must be safe, but that’s not always true.
How to fix it: Follow your manufacturer’s rules about crash replacement. If your seat does need to be replaced, check with your insurance company (many will cover the cost of a new one). It may feel frustrating to retire a seat that seems perfectly good, but replacing it is the only way to make sure your child is protected for the next ride.
You’re Covering the Car Seat with a Blanket
How to check: It’s common to see a blanket draped over an infant seat for naps, cold weather, or to block out light. But if the blanket completely covers the car seat—especially when it’s rear-facing—it can restrict airflow inside.
The potential danger: A covered seat can trap heat and limit ventilation, raising the risk of overheating. Babies may also end up rebreathing their own exhaled air under the blanket, which can reduce oxygen levels. Even a thin muslin drape can create a warmer, less breathable environment than you realize, especially in a warm car or on a sunny day.
How to fix it: Instead of fully covering the seat, use a breathable canopy that allows for plenty of airflow or a shade designed specifically for your car seat (always check that the manufacturer approves it). For warmth, dress your baby in layers and add a blanket over them once they’re harnessed. This way, your little one stays cozy and protected without compromising fresh air.
.
Have More Car Seat Questions?
Car seats can feel complicated, but you don’t have to figure it out on your own. Strolleria is an authorized retailer for Cybes, Romer, UPPAbaby, Clek, and other leading brands, and our team is here to help you navigate installation, fit, and safety. Reach us anytime at cs@strolleria.com.
