The Carseat Lockoff Guide

What is a lockoff and which carseats have them?

UPDATED: July 2019

As LATCH weight limits shrink due to federal standards, more and more carseats require using the seatbelt to install once the child reaches a certain weight. In some cases the LATCH weight limit can be as low as 25 or 30 lbs. (child weight). The problem with seatbelt installations is that most parents have no idea how to lock the seatbelts in their vehicle in order to properly install a carseat or infant seat base. Ask the average parent or caregiver what a “switchable retractor” is or a “locking latchplate” and you’ll probably get a very confused look in response.

This is why every car seat in North America should come with a built-in lockoff! If you are installing with a seatbelt instead of lower LATCH anchors and your carseat has a lockoff device – use it and you will never have to worry about LATCH weight limits or understanding pre-crash locking features on vehicle restraint systems.

Function of built-in lockoff device: A lockoff device can serve more than one function but its main purpose is to cinch or clamp the seatbelt in such a way that it cannot loosen and your tight carseat installation stays tight!  

2019 List of Carseats with Lockoff(s)

Rear-Facing Infant Seats
Baby Jogger City GO 
Britax B-Safe 35 | B-Safe 35 Elite | B-Safe Ultra | Endeavours
Chicco KeyFit | KeyFit 30
Chicco Fit2 Infant & Toddler
Clek Liing
Combi Shuttle
Evenflo LiteMax | LiteMax DLXSafeMax Infant
GB  Asana 35 DLX
Graco SnugRide 35 LX Click Connect
Graco SnugRide SnugLock (all models)
Hauck ProSafe 35
Nuna Pipa | Pipa Lite
Peg-Perego Primo Viaggio 4-35 | Primo Viaggio Nido
phil&teds Alpha
Safety 1st onBoard 35 Air & onBoard 35 Air+
UPPAbaby Mesa
Urbini Petal | Sonti
Convertible Seats
Britax AllegianceEmblem
Britax  ClickTight convertibles (all models)
Chicco NextFit SportNextFit ZipNextFit Zip Air | NextFit Zip Max
Clek Foonf | Fllo
Combi Coccoro
Cybex Eternis SSirona M
Graco 4Ever DLX*4Ever Extend2Fit*
Graco  Recline N' Ride
Graco TrioGrow SnugLock
Maxi-Cosi Magellan | Magellan Max
*forward-facing only lockoff
Forward-Facing Combination Seats
Britax Frontier ClickTight | Pinnacle ClickTight
Chicco MyFit | MyFit LE
Graco Nautilus 65 LX featuring TrueShield Technology
Graco Nautilus 65 DLX
Graco Nautilus SnugLock  ©2019 All Rights Reserved

Lockoffs on Infant Seat Bases

There are different types of lockoffs that require different routing so make sure you are following the directions that came with your carseat. Never assume anything. Below we discuss the two most common types of lockoff systems.Lockoff just for shoulder belt portion of the lap/shoulder belt

  • Bases with these types of lockoffs will have a lockoff on each side of the base but you only use one lockoff–  on the side where the shoulder belt goes up to the retractor.

keyfit base lockoff


Two lockoffs on base but only use one of them!

Single lockoff device

  • clamps both portions of the seatbelt (lap belt and shoulder belt)

Graco SR35 lockoff



Convertible seats with lockoffs will usually have them for both rear-facing and forward-facing beltpaths

Britax Allegiance and Emblem lockoffs (old-style Britax G4.1)


Original Chicco NextFit lockoffs (just for shoulder belt portion)

nextfitlockoffopen  nextfitlockoffclosed

Clek Foonf & Fllo lockoffs (different types of lockoffs for RF & FF beltpaths)

Clek Fllo FF lockoff Clek Fllo RF lockoffs

Forward-Facing Combination Seats Lockoffs

Nautilus 65 DLX model 


Chicco MyFit (this lockoff design can also be found on all current NextFit convertible seats)

ClickTight Technology (available on certain Britax models): The ClickTight compartment acts as a lockoff too!

Britax Frontier 90 - Desert PalmBritax Advocate CT - open CT compartment stock

Stay tuned for updates when additional products with lockoff features become available.


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