LATCH stands for Lower Anchors and Tethers for Children. It has been in effect since 2002 and is meant to make it easier to install child car seats. Instead of using seatbelts to secure the seats, LATCH employs attachments that use the lower anchors and tethers found in vehicles and on child car seats.
In a rule that became effective in February 2014, NHTSA advises parents not to use the lower anchors of LATCH if the combined weight of the child and the car seat is 65 pounds or more, according to NHTSA. The agency does allow car seat makers to round up child weight maximums to whole numbers, such as 40 pounds instead of 38, so the total combined weight maximum may be closer to 70 pounds for a few car seats.
Once children and their seats are past the weight limit for the lower anchors, parents can secure the child seat using the safety-belt system. The 2014 revision to the rule only applies to the lower anchors. Use of the tether strap that is attached to the top anchor is not affected.
Generally, top tethers are used for forward-facing car seats and can be used either with LATCH or seatbelts, according to NHTSA. But the agency recommends first checking with the makers of the seat and the car to be sure.
The switch away from lower anchors at the combined 65-pound weight limit is a safety precaution, according to NHTSA. In discussions with the agency, vehicle manufacturer associations and some makers of child car seats supported the combined weight label so consumers would know how heavy a child could be without potentially overloading the LATCH anchors.
More Car Seat Resources
Here is more information for parents to ensure that their young passengers are riding safely: