How to install a forward-facing car seat with LATCH
The short answer
To install a forward-facing car seat with LATCH, clip the seat's two lower connectors onto the vehicle's lower anchors, press the seat firmly down and back while tightening the lower anchor strap, then attach and tighten the top tether. Finish by checking that the seat barely moves at the belt path and that the harness fits your child correctly.
LATCH stands for Lower Anchors and Tethers for Children. It is a system of fixed metal anchors built into the vehicle. It lets you secure a car seat without the vehicle's seat belt. Forward-facing seats use two parts of it. The lower anchors are a pair of metal bars tucked into the gap where the seat cushion meets the seatback. The top tether anchor is a separate attachment point behind the seating position, which the car seat's top strap clips onto.
Several conditions change the answer:
Lower anchors have a weight limit. Your car seat's label and manual state the maximum child weight for using them. Once your child exceeds that weight, you must install the seat with the vehicle seat belt instead, while still using the top tether. Not every seating position has lower anchors. Many vehicles have no dedicated lower anchors in the middle rear seat. Most manufacturers do not allow LATCH and the seat belt to be used together. Use one or the other unless your car seat manual specifically permits both. Anchor locations, the positions approved for car seats, and installation details vary by vehicle model and car seat model. Your vehicle owner's manual and car seat manual override any general guide, including this one.
Before you start
Gather the following:
The car seat manual and the labels on the seat itself; The vehicle owner's manual, especially the child restraint section; The car seat, with its lower anchor connectors and top tether strap
Then confirm these points:
Your child is within the car seat's forward-facing limits. Check the height, weight and any age requirements in the manual. Rear-facing for as long as the seat allows is widely recommended, so make sure forward-facing is the right stage for your child. The car seat has not expired. Many seats have an expiration date on a label or molded into the shell. The car seat has not been in a crash. If it has, check the manufacturer's replacement guidance. The seat is not under a recall. The vehicle seating position you plan to use has both lower anchors and a top tether anchor. The vehicle manual will tell you.
Step-by-step installation
1) Locate the lower anchors and top tether anchor
Find the lower anchors by feeling into the seat crease or looking for small labels or symbols on the seat fabric. Then find the top tether anchor. Depending on the vehicle, it may be on the back of the vehicle seat, the rear shelf behind the headrests, the roof, the floor or the cargo area. Your vehicle manual shows the exact location.
Stop condition: do not attach the tether to a cargo hook, tie-down ring or seat frame part unless the vehicle manual identifies it as a tether anchor. Some cargo hooks look similar but are not designed to hold a car seat in a crash.
2) Check whether the center seat is allowed
If you want the middle seat, check whether it has its own dedicated lower anchors. Some vehicles allow a seat to borrow the inner anchors from the two outer positions. Others prohibit it. Only borrow anchors if both your vehicle manual and your car seat manual allow it. If either says no, use a seat belt installation with the top tether in the center, or choose an outer position with dedicated anchors.
3) Set up the car seat for forward-facing use
Put the car seat in its forward-facing configuration. Depending on the model, this may involve:
Setting the recline position the manual specifies for forward-facing use; Routing the lower anchor strap through the forward-facing belt path, which is usually behind the child's back. This path is different from the rear-facing one. Removing the top tether from its storage spot
Fully loosen the lower anchor strap and the top tether strap so you have slack to work with.
4) Remove the headrest if required
Some vehicle headrests push the car seat forward or get in the way of the tether route. Your vehicle and car seat manuals will tell you whether to remove or adjust the headrest. Do not remove it unless the instructions call for it.
5) Attach the lower connectors
Place the car seat flat on the vehicle seat, facing forward. Its back should rest against the vehicle seatback. Clip each lower connector onto its anchor. Depending on the design, the connector may click or a visual indicator may change color. Tug each connector to confirm it is locked on. Make sure the strap is not twisted.
6) Tighten the lower anchor strap
Press the car seat down into the cushion and back into the seatback, using your hand or knee. While you hold that pressure, pull the tail of the lower anchor strap to remove the slack. Some seats tighten more easily if you pull the strap back toward the inside of the car seat, or if you feed slack through from the opposite side first. Some have a built-in tensioning or lock-off system instead. Follow your car seat manual's method.
7) Attach and tighten the top tether
Route the top tether over or around the vehicle seatback and headrest as the manuals direct. Clip it to the tether anchor, keeping the strap flat and untwisted, then pull it snug. The top tether limits how far the child's head moves forward in a crash. Use it for every forward-facing installation, with LATCH or with the seat belt, unless your manuals specifically say otherwise.
Stop condition: if your seating position has no usable top tether anchor, do not skip the tether and carry on. Check the vehicle manual or contact the vehicle manufacturer or a dealer about tether options. Choose a seating position that has a tether anchor if one is available.
Check the installation
Hold the car seat at the belt path, where the lower anchor strap passes through it, not at the top of the seat. Pull it side to side and front to back. A common guideline is that a correctly installed seat should move less than one inch in any direction at the belt path. Confirm the test in your car seat manual. If the seat moves more than that, repeat step 6 with more pressure on the seat.
Also confirm the following:
Both lower connectors are latched and the strap is not twisted. The top tether is attached to an approved anchor and is snug. The seat is at the recline angle the manual specifies for forward-facing use. The seat belt is not also securing the car seat, unless the manual allows it.
Check the harness fit
A tight installation protects your child only if the harness fits correctly. Each time you buckle your child in, check the following:
For forward-facing use, the shoulder straps come from slots at or just above the child's shoulders, unless the manual says otherwise. The harness is snug. You should not be able to pinch a horizontal fold of strap at the child's collarbone. The chest clip sits at armpit level. The straps lie flat, without twists. Bulky coats are off. They can create hidden slack in the harness.
When to stop and get help
Stop and seek guidance if any of the following applies:
The seat still moves too much after several tightening attempts. The vehicle and car seat manuals seem to conflict. You cannot find or reach the anchors. Any connector, strap, buckle or anchor looks damaged. Your child has reached the lower anchor weight limit and you are unsure how to switch to a seat belt installation.
In the US, certified Child Passenger Safety Technicians (CPSTs) are trained to check and help with car seat installations. Your car seat or vehicle manufacturer's customer service can also answer model-specific questions.
Damaged or missing vehicle anchor hardware is a job for a dealer or qualified service technician. Do not repair or modify it yourself.
What this guide cannot confirm
This guide covers the general LATCH procedure only. It cannot tell you the following for your setup:
The exact lower anchor weight limit for your car seat; Where the tether anchors are in your vehicle; Which of your vehicle's seating positions permit anchor borrowing; The required forward-facing recline for your seat
Each of these depends on your vehicle's make, model and year and on your car seat model. Check them in the two manuals before you drive.