What Is A Tether?

Everything You Need to Know about Using a Tether with Your Carseat
Updated June 2021

There are so many confusing things about carseats for parents and tethers rank right up there with “do I use LATCH and the seatbelt together?” (the answer to that one is a wishy-washy no). We have a tether use rate of much less than 50% in the U.S., about the same as it was back in the mid-70s. Yes, you read that correctly! It’s gone up and down, but it’s still right around the same—pathetic. Even after teaching a child passenger safety technician class and going over tethers with them—when to use them, how important they are for safety—I still got the deer-in-headlights look from some of the new techs when I quizzed them about tether usage. So if my trained technicians are hesitant about when to use a top tether (how about all the time forward-facing!), I can only imagine the confusion parents are feeling. Without further ado, let’s get to it and learn about tethers.

What is a tether and where is it found?

A tether (aka top tether, top tether strap, top strap) is a long piece of seat belt material that has a clip on the end located at the top back of a convertible, all-in-one (3-in-1 or 4-in-1 included), or combination carseat. A convertible carseat rear-faces for a baby, toddler, and sometimes preschooler, then turns forward-facing for an older child. An all-in-one rear-faces, forward-faces, then becomes a belt-positioning booster for a school-aged child. A combination carseat is a forward-facing harnessed carseat that converts to a belt-positioning booster seat.

When the carseat is used forward-facing, the tether is attached to a vehicle tether anchor and the tether secures the top of the carseat to keep it from moving. Oh, and can I say just one little thing before moving on? It’s most definitely not a teether.

Why should I use a tether?

This simple strap can keep a child’s head from moving forward—a movement called “head excursion”—in a crash by 4-6”. That’s really a huge number in the carseat world! It can mean the difference between the child sustaining head injuries from hitting the front seat (yes, even while harnessed) or side pillar in a crash and walking away giggling. Tether use mitigates serious neck injuries by reducing head acceleration and neck loading. By attaching the carseat to the vehicle more tightly, the tether allows the vehicle and carseat to absorb more of the crash forces, not the child.

Federal standards allow head excursion of 32” when a tether is not used, 28″ when the tether is connected. Let’s see what that 32” looks like inside a real car instead of on a crash test sled:

head excursion numbers

Notice that 32″ runs into the front passenger seat. This vehicle is a mid-sized SUV with a very comfortable 2nd row for space. Think about how 28″ or 32″ would look in a compact or sub-compact car. Here are two more tether comparison pictures:

  Safe-n-Sound/Britax test sled showing carseat movement

How easy is a tether to use?

Clip it on, snug it up, and go. Yep, it’s that easy. Why haven’t you done it yet? Ohhhh, right, if it was that easy, you would have done it already. Of course! Sometimes there are snags to using it, but that’s why you have techs at your disposal to call or question at car-seat.org and our Facebook help group. But first, have you consulted your manuals? That’s right, you’ve got to read your carseat and vehicle manuals. Power to parents and caregivers!

A bit o’ tether history

Tethers have been on forward-facing carseats since September 1, 1999, and they’ve been on Canadian carseats since 1980. Tether anchors, the hardware in vehicles to which you attach the tether, were phased in beginning with vehicles manufactured on September 1, 1999 (model year, aka MY, 2000), and all minivans, SUVs, and light trucks had to have tether anchors starting September 1, 2000 (MY 2001). Keep in mind that the actual date of manufacture of the vehicle is more important than the MY because a vehicle can be considered a particular MY vehicle before the September 1 release date. Got it? Look at the sticker on the driver’s side door and it should tell you when it was made. Now if all of that is gibberish to you and your car is MY 2001 and newer, don’t worry about a thing—you’ve got tether anchors, so use them!

What if the car you are driving was made before September 1, 1999, even maybe in 1995. You’re definitely thinking that it doesn’t have tether anchors. That may not be a problem—maybe. Most vehicles can be retrofitted with tether anchors—IF you can find the parts now. If you’re handy, you may even be able to DIY. Awesome! Because it is a safety feature, some vehicle manufacturers offer a free installation program, others will do it for a reduced fee. If you want to DIY, all you need is a part number (again, we can help you at our help groups: car-seat.org or Facebook), a torque wrench plus some instructions, and about $15 for the part. For installation programs, contact your service department with the following information:

Manufacturer Program
Chrysler, Dodge, Jeep/Eagle/Plymouth Tech. Service Bulletin 23-014-15; addt’l info in the Warranty Bulletin D-08-33

➣ Only parts are available for the MY 2000 Jeep Cherokee outboard position; MY ’93-’98 Jeep Grand Cherokee/Grand Wagoneer center position; MY ’90-’94 Plymouth Laser and Eagle Talon center or outboard positions, bolt part only

Ford, Lincoln, Mercury R7C (dealership billing code)
GM (Buick, Cadillac, Chevrolet, Geo, GMC, Hummer, Oldsmobile, Pontiac, Saturn) GM no longer honors Service Bulletin #99-09-40-004B
Toyota/Lexus Partnered with SafetyBeltSafe USA; apply through SafetyBeltSafe USA

So your dh went and bought a used Hummer because he thought they looked cool and he for sure was going to use it hunting. Turns out it sits around a lot because of the gas mileage, but every now and then he likes to take the kids in it. You go out to look for the tether anchors but can’t find any. You must be blind—it’s a 2003 vehicle, it’s supposed to have tether anchors, right? Nope, it’s exempted because it weighs more than 8,500 lbs. Fortunately most vehicle manufacturers do put tether anchors in large vehicles because they are such a valuable safety feature. After your dh sells the Hummer, he wants to buy a convertible BMW. Sigh. Stop him now! Convertibles are exempt too ;).

Where can I find tether anchors?

Federal standards (FMVSS 225 for you research types) require tether anchors in at least 2 positions to go with the lower anchors aka LATCH (the T stands for Tether—now you can be smart in front of all your friends!), 3 if there are 3 rear seating positions. Larger vehicles, like minivans and 3-row SUVs, may have more, but they aren’t required (buyer beware!). Tether anchors can be found just about anywhere. They can be in the ceiling of a wagon or SUV, in the back ledge of a sedan, in a back wall of a wagon, SUV, or van, in the cargo area, on the back of the vehicle seat, or under the vehicle seat.

OK, you’ve convinced me. How do I tether my carseat?

Crack open your vehicle manual to the child seat/safety section (it’s right behind the seat belt section) and find your tether anchor. You’ll want to use the tether anchor directly behind the seating position where you’ve installed the forward-facing carseat; meaning if you’ve installed the carseat on the passenger side (we call that outboard), you have to use the passenger outboard tether anchor. You can’t use the center tether anchor for that seat. Tethers can be up to 20° off-center, but that’s to account for things like speakers that may be in the way or to give vehicle manufacturers more leeway in where they can put the anchor.

What if you can’t find your vehicle manual? Google, my friend, Google! Simply type in your vehicle model year, manufacturer, and make, and use the words “owner manual” and there will be several sites to help you (e.g., “2018 Chevrolet Traverse owner manual”). Most vehicle manufacturers now have their owner’s manuals online for easy access.

Another thing your vehicle manual can help you with is how the tether should be in relation to the vehicle head restraint. Some manuals specify that the tether should go over the top of the vehicle head restraints, others specify it should go under, and perhaps yours specifies that the head restraints should be removed. What if your carseat has a dual-strap tether, found on Britax carseats? Read both the carseat manual and the vehicle manual! You may not be able to fit the tether in between the posts of the vehicle head restraint and your question may be answered for you.

What if I’m not sure this metal thing in the cargo area is a tether anchor?

If you’re not sure the metal loop in your cargo area is a tether anchor, then don’t use it. Cargo loops aren’t always tested to the specifications that tether anchors are, so it may not hold in a crash. If you can’t find your vehicle manual and your best friend Google is moody today, order a manual for yourself from your dealer or eBay so you can be sure that your child is safe.

How do I tether my carseat in my truck? It looks really complicated!

Tethering a carseat in a truck definitely requires reading the truck’s owner’s manual! This isn’t a one-size-fits-all type of answer. In some extended/quad cabs, the truck manual will have you route the tether through a loop (either coated metal or a strap) at the top of the truck seat over to the loop at the adjacent truck seat. The owner’s manual will tell you whether or not you will have to place the tether in front of or behind the head restraint posts. Some trucks, like the Honda Ridgeline, have you route the tether around a metal guide and down to a tether anchor on the floor next to the truck seat or directly behind the carseat (center seating position).

Sierra center loop Sierra driver to center tether Tundra passenger to center

When should I use the tether?

All the time a child is forward-facing and harnessed! However, all manufacturers, vehicle and carseat, put weight limits on their equipment. Tether anchors are no different and while carseat tether weight limits are the the weight limits of the carseat, vehicle manufacturers put varying weight limits on their tether anchors based on testing. They may list this weight limit in the owner’s manual or they may not. I’m going to talk out of both sides of my mouth here, lol, and say that you should pay attention to those weight limits, but make an educated decision about when to stop using the top tether.

Here’s what we know: having a maximum weight limit for tether anchors implies failure at that limit. We don’t have evidence of injury if there is failure, even after decades of required use in Canada. Because the tether works in conjunction with either the seat belt or the lower LATCH connectors, it’s less likely to fail than if the carseat were installed with just the tether alone. In the aftermath of a crash, the tether has done its job of reducing injury and slowing the child’s body during the early part of a crash. If any hardware fails, it tends to bend/distort, not all out fail and flail about the vehicle. It’s exactly the taller, heavier children who need the benefits of tethers because they are more likely to have higher head excursion. Ultimately it needs to be a parental decision, but as a parent, you need to have all the information available.

Am I required to use a tether?

No, not by law (unless you’re in Canada). You’re also not required by law to feed your children healthy food, but you do it anyway because it’s good for them, right? Same thing here. If you are using the lower LATCH connectors, you should use the top tether because it’s part of that system and the system works better when all pieces are used. And you should always use the tether when installing a carseat with the seatbelt. It’s a safety feature, so why wouldn’t you use it?

A few carseats do require the use of a tether in specific situations, which may limit their use in your vehicle if you don’t have a tether anchor or have a low weight limit on it and you choose to remove the tether once your child reaches the weight limit. As part of your research for a carseat, you may want to check out its owner’s manual and see if it requires tether use if you’re considering placing it in a position where a tether anchor isn’t available.

How about use of the tether in booster mode?

Some combination seats (forward-facing harnessed seats that convert to a belt-positioning booster) allow the use of the tether with the lower anchors when used as a booster. This isn’t as a safety feature for the child, but more for the other passengers in the vehicle when the child isn’t riding in the seat. The tether keeps the carseat attached to the vehicle in the event of a crash so it doesn’t fly into the driver or a passenger. Best practice, of course, is for the child to buckle it in whenever he gets out of it. Real life, at least in my family, is that the seatbelt rarely gets buckled over the booster.

What do I take from this article?

Well, you should tether your forward-facing carseat, of course! Let’s get a 100% tether use rate. Every time you install a forward-facing carseat, either with a seatbelt or with LATCH, attach the tether. It’s simple. If you don’t have a tether anchor, look into getting one installed in your vehicle TODAY. Educate your friends and family on the importance of the tether strap.

Giving proper credit where proper credit is due: the LATCH manual by the SafeRideNews team is *the* authority on tethering and retrofitting tether anchors and SafetyBeltSafe USA’s Technical Encyclopedia is every newbie and experienced tech’s go-to information guide.


  1. Ali March 2, 2019
  2. Ali March 2, 2019
  3. Christina February 21, 2018
    • Heather February 21, 2018
  4. Cnidaria September 30, 2017