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The Best Trailer Hitch Coupler Locks for Preventing Trailer Theft

If something is on wheels, it's a target for thieves, and this includes your trailer. Trailer coupler locks (also referred to as trailer hitch locks or trailer tongue locks) are a simple, affordable way to deter the bad guys and make sure your trailer stays yours.There are different types of trailer hitch locks, and the best one for you depends on what exactly you want to accomplish. Do you want to protect your trailer when it's hanging out unattached in your driveway? Or are you equally concerned about someone unlatching your coupler in the parking lot?Check out our guide for the top trailer hitch locks below and find the ideal lock to secure your rig.
NOTE: Keep in mind that NO lock is 100% foolproof. Trailer hitch locks are designed to provide a deterrent and make it difficult for would-be thieves to easily take off with your trailer. Think of it like locking your front door. Is it going to keep out a bad guy who's absolutely determined to get into your house? Probably not. Are locks a basic, affordable protective measure you can take to keep the average bad guy away? Of course they are; that's why we use them.
Fastway Universal Trailer Coupler Lock
Fastway Universal Trailer Coupler LockWHAT WE LIKE: Hefty Keyed-Alike Protection for Any Coupler SizeThis is for you if:This burly lock by Fastway announces to everyone that your rig would be more trouble than it’s worth to steal. It allows you to keep your detached trailer in your driveway, storage facility, or other parking space without worrying about greedy eyes. The integrated tube key lock cylinder, anti-drill pin, and bolt-blocked locking system all work together to provide superior security to other hitch locks on the market. These Fastway locks are compatible with 1-7/8”, 2” and 2-5/16” couplers, so you can use the single lock for multiple trailers. If you need more than one, the locks can be keyed alike for added convenience. This is NOT for you if:If you're looking for a lock to protect your trailer when you're hitched up, skip this one and check out lock #2 below. If you're looking for a coupler lock with a bit more visibility, you'll like the etrailer option at #3.
Bulldog Lifelong Trailer Coupler Lock
Bulldog Lifelong Trailer Coupler LockWHAT WE LIKE: Protection With Trailer Attached + Added Road SafetyThis is for you if:You have a trigger-style ball coupler and want protection both on and off the road. The Bulldog Lifelong Trailer Coupler Lock secures the trigger latch on your coupler, ensuring that the trailer can't be removed from your tow vehicle when it's locked onto your hitch ball. This means if you leave your hitched up trailer unattended in a parking lot, no one is able to unhitch your trailer from your hitch ball and drive away with it. This style lock also provides an added layer of security when you're towing by further ensuring your trailer won't come unhitched as you drive down the road.The lock also deters theft even when your trailer isn't hitched up. Just secure the lock over your coupler when your trailer is parked in your driveway or in storage. The lock will prevent anyone from being able to hitch your trailer to their own vehicle since the trigger latch won't properly engage.Essentially, if you're looking for a cost-effective security device to protect your trailer at all times, this Bulldog lock is perfect for you.This is NOT for you if:If you don't have a trigger-style coupler latch. This lock is also keyed unique, so if you prefer a keyed-alike option, this lock isn't for you.
etrailer Coupler Lock
etrailer Keyed-Alike Coupler LocksWHAT WE LIKE: Keyed-Alike Protection at a Great ValueThis is for you if:If you want one key to rule them all, you want these hitch coupler locks by yours truly. We know how annoying it is to have a dozen keys to keep track of, which is why our locks all offer a keyed-alike option. You can purchase locks for any size hitch as well as multiple coupler latch sizes. This means you can purchase locks for multiple trailers—and still use a single key for them all. Plus, our locks are made of rustproof aluminum, so they’ll hold up to the elements. Just select “keyed alike” in the drop down menus to make sure all locks utilize the same key. This is NOT for you if:Our locks are a great theft deterrent at an excellent value, but if you're looking for a keyed-alike option with a little more heft, check out the Blaylock EZ Lock below.
Blaylock EZ Lock
Blaylock EZ LockWHAT WE LIKE: Aircraft-Grade, Rustproof ConstructionThis is for you if:If you want one of the burliest, un-stealable, USA-made hitch locks on the market. This lock is compatible with trigger-, latch-, and handwheel-style couplers, so it'll work for most trailers. The heavy-duty bracket fits around your trailer's coupler and is secured with a steel pin, preventing towaway theft when your trailer is unattached. The included stainless steel padlock secures the pin in place.In order to break this lock, you'd have to cut through that 3/4" thick steel pin. Can it happen? Yes. But a thief would need an opportunity to sit down with this lock and some power tools in order to do it, so it would be anything but easy. The lock is made of aircraft-grade aluminum, so it's corrosion-resistant as well as bad-guy-resistant. This lock can be keyed alike.This is NOT for you if:If you're looking for a low-cost deterrent to scare off thieves looking for an easy target, this is probably overkill and may cost more than you want to spend. This lock also does not protect your trailer when it is hitched to your tow vehicle.Also note that this lock, at 6-1/4" long x 4-1/4" wide x 5-1/4" tall, isn't the easiest to store unless you have room in your trailer or in a truck bed tool box.
BOLT Trailer Coupler Lock
5. BOLT Trailer Coupler Lock (Vehicle-Specific)WHAT WE LIKE: Convenient Security With No Extra KeysThis is for you if:If you don't mind paying a little more for convenience, consider a BOLT Trailer Coupler Lock to prevent towaway theft when your trailer is unhitched. The unique design fits most coupler and latch styles, so chances are, your trailer could use this.If you want a hefty lock that looks intimidating to would-be thieves, you'll appreciate the burly, bright-red design. But most of all, you'll love the BOLT's unmatched convenience. Why? The lock codes permanently to your vehicle's ignition key. This means NO extra keys to keep track of—your vehicle key is all you need. The 6-plate tumbler sidebar on the lock prevents picking or bumping, so it's secure as well as convenient.This is NOT for you if:Although many vehicle years, makes, and models are compatible with these vehicle-specific locks, not all are. Check your model compatibility in the product description before purchasing. Also, this may not be the lock for you if you're planning to get a new vehicle soon, as the lock can only ever be coded to one vehicle key.Also note that this is a seriously hefty lock, and its size (over 6" X 6" X 6") makes it a beast to store when not in use.
Amber S.
About Amber S.As a content writer for etrailer, I might spend my morning loading and unloading a bike on five different bike racks to figure out which is easiest to use. I might be in the parking lot, taking pictures of an impressive RV battery setup our techs came across in the shop and discussing the benefits of the setup with the owner. I might spend an afternoon in a manufacturer training classes for some hands-on experience with new products, and then sit down to assemble all this information into a coherent article.At etrailer, one of our core values is that we are always learning, and I learn something new every day. I start each morning with the goal in mind of taking all of this information and figuring out the best way to answer the questions people ask us (and the ones they don’t know to ask yet), and helping people get the solutions they need to make their lives easier, safer, and more fun. I’m a DIYer at heart, so it brings me great joy to help a fellow DIYer find what they’re looking for, whether that’s a product, an answer, or a community.
Related ProductsWritten by: Amber S.Updated On: 2/6/23

Lock M.


Bet I could pick every one of these in under a half hour.

Lock D.


@LockM cool story bro
Etrailer Expert

Mike L.


@LockD It was entertaining!

Mark S.


Hi I recently bought a new Lamar trailer w / a Demco adjustable latch coupler. Having a difficult time finding a ball lock for this. Any research and recommendations?? Thanks!

David B.


Hello Mark, that's a great question. That depends on the size of the ball for the coupler a 2" or a 2-5/16" ball. Would you tell me the model number of the coupler? This will tell me what style will work for you.

Mark S.


@DavidB Demco EZ Latch 2” ball 10000# GVWR SAE J684 CL4 I was hoping to purchase the Ft. Knox (Curt) lock) or fairly beefy lock I may just swap out the coupler as the later itself is at a weird angle. Kind of frustrating.

Mark S.


@DavidB My concern is that the ball hitch is lower than the neck. Whereas most are level so box could easily fit over.
See All (5) Replies to Mark S. ∨



Hi, Any protection for coupler including bolt and nut that attach to tongue trailer? If you lock the ball but bolt and nut still open, prepared thief can easily open bolt and not of attached coupler and replace coupler then pull up the trailer.

Etrailer Expert

Jon G.


I can't say that I've heard of a way to secure the mounting hardware for your trailer coupler. What we usually tell people is that even locks are beatable given enough time, talent, and resources. In your scenario I would say the same thing. If someone is willing to bring the proper tools to remove your coupler entirely then they could very well have other tools like a saw to just cut the coupler off if you have the mounting hardware secured.

Bill J.


#2 will NOT prevent theft unless the pin that holds the vehicle hitch is also made unremoveable...otherwise all the thief would have to do is remove the clip. remove the pin and then roll the whole trailer backward.

Etrailer Expert

Chris R.


The pin on the Bulldog Lifelong Coupler Lock # BD580403 cannot be removed without using the key in the main cylinder. No lock will "prevent" theft completely but this unit will do a really nice job of making it awfully difficult.

Steven F.


What about fifth wheel locks?

Etrailer Expert

Chris R.


This particular article just focuses on bumper pull couplers. I've linked our full selection of king pin locks below that you can look through for your 5th wheel!



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