When our oldest figured out how to open a car door from the inside at age three, it became one of those heart-stopping parenting moments that changes your behavior permanently. We were parked at the time, thankfully, but the thought of what could have happened on a busy road made me immediately learn about the child safety lock feature that had been built into our car all along.
Child safety door locks are one of the simplest and most overlooked safety features in every vehicle — and they work alongside your car seat to keep young passengers secure. Here’s everything you need to know about finding, using, and maintaining them.
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What Child Safety Door Locks Do
Child safety locks disable the interior door handle on rear doors so the door can only be opened from the outside. When engaged, your child can pull the interior handle all day long and the door won’t open. This prevents curious toddlers and young children from opening doors while the vehicle is moving — which could result in the child falling out of the vehicle or the door striking objects, other vehicles, or pedestrians.
These locks are a standard feature in virtually every car, truck, SUV, and minivan sold in the US. They’ve been required on rear doors for decades, so even older vehicles will have them. The locks only affect the rear doors — front doors don’t have child safety locks, which means in an emergency, an older child in the front seat can always exit the vehicle.
Finding and Engaging the Lock in Your Vehicle
There are two types of child safety door locks, and which one your vehicle has depends on the make, model, and year.
Manual child safety locks are by far the most common. Open the rear door and look at the edge of the door itself (the side that faces the door frame when closed). You’ll see a small lever, switch, or slot. On most vehicles, you slide a lever to the “lock” position, which is usually indicated by a padlock icon. Some older vehicles use a small slot that requires your key or a flathead screwdriver to turn. You need to do this for each rear door individually.
Electronic child safety locks are found in newer and higher-trim vehicles. These are typically activated from the driver’s controls — either through buttons on the driver’s door panel or through the vehicle’s infotainment system under a “locks” or “safety” menu. Electronic locks let you control both rear doors from the driver’s seat without having to physically open each door.
If you’re not sure which type your vehicle has, check your owner’s manual. It will show the exact location and operation method for your specific model.
When to Use Child Safety Locks
I recommend engaging child safety locks as soon as you start transporting a child who has the dexterity to reach and pull a door handle — which for most kids is somewhere around age 2 to 3. Keep them engaged until the child is old enough to understand car safety rules and you trust their judgment about when it’s appropriate to open a door (typically around age 8-10, though this varies by child).
Child safety locks complement your car seat setup. While the car seat’s harness keeps your child secured in their restraint during a crash, the door lock prevents them from exiting the vehicle at inappropriate times — at a stoplight, in a parking lot, or while you’re driving. Both systems work together to keep your child safe.
Important Safety Considerations
There are a few things to keep in mind when using child safety locks. First, when the lock is engaged, anyone sitting in that rear seat can only exit by opening the door from the outside or by lowering the window and using the exterior handle. Make sure older children and other passengers in the back seat know this, so they’re not confused or frightened if they need to exit the vehicle.
In an emergency where you need everyone to exit the vehicle quickly, rear seat passengers will need someone to open their doors from the outside, or they’ll need to climb to the front seats. Some parents choose to only engage the child lock on the door closest to their young child rather than both rear doors, leaving the other rear door operable from inside for older siblings or other passengers.
You should also consider using your vehicle’s power window lock feature (usually a button on the driver’s door) to prevent children from operating the rear windows. Power windows can generate enough force to injure small fingers and hands, and children have been seriously hurt by playing with window controls.
Checking That Your Locks Work
It’s a good habit to test your child safety locks periodically. Engage the lock, close the door, then try to open it from the inside. It should not open. Then open it from the outside to confirm it opens normally from that side. If the lock doesn’t engage or disengage properly, have it inspected by your mechanic — the mechanism can sometimes get stuck, especially in older vehicles or in climates with extreme temperatures.
Also check that you haven’t accidentally disengaged the lock. It can happen when a mechanic works on the door during service, or if someone unfamiliar with the feature bumps the lever while loading cargo through the rear doors.
Child Safety Locks Are Part of a Bigger Picture
Door locks are just one piece of keeping young passengers safe. The foundation is always a properly installed, correctly used car seat that matches your child’s size. For help choosing the right seat, see our best-rated convertible car seats guide. If you’re not sure your car seat is installed correctly, get a free check from a certified technician through NHTSA’s technician locator.
And if you’re concerned about hot car safety — which is closely related to door and lock awareness — read our guide on why hot cars are deadly for kids and our coverage of hot car prevention technology.
