The Best Trailer Locks for Transporting Large Tools or Materials

An easy-to-use trailer lock keeps the trailer and its contents secured to your vehicle so it doesn’t become a target for theft.

Best Overall

Best Trailer Lock Options: Trimax UMAX100 Premium Universal Dual Purpose Coupler Lock

Trimax UMAX100 Premium Universal Dual Purpose Lock

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Best Bang For the Buck

Best Trailer Lock Options: Reese Towpower 7014700 Tow 'N Store Lock Kit

Reese Towpower 7014700 Tow u0026#039;N Store Lock Kit

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Best Receiver

Best Trailer Lock Options: Master Lock 2866DAT

Master Lock 2866DAT 1/2 in. and 5/8 in. Swivel Head

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A trailer hitch lock helps prevent the trailer from becoming the target of thieves, whether it’s connected to a vehicle at a campsite or in the driveway at home. Trailer hitch locks come in different types.

Some devices secure the actual ball and tongue of the hitch, so the lock must be removed to connect the trailer to another vehicle. Other trailer locks replace the trailer’s hitch pins with locking pins, so the hitch can’t be removed from the trailer or the vehicle. These pins also slot through the hole in the locking latch to prevent the latch from opening. This locks the trailer hitch to the vehicle if it’s already connected. If not connected, the pin prevents ne’er-do-wells from connecting the hitch to their vehicle unless they first remove the lock.

Choosing the best trailer lock to keep your trailer and its contents safe depends on the lock’s compatibility with the hitch, as well as the durability and strength of its material. This list of top products includes several lock options to help you find the best trailer lock to secure your trailer and belongings.

  1. BEST OVERALL: Trimax UMAX100 Premium Universal Dual Purpose Lock
  2. BEST BANG FOR THE BUCK: Reese Towpower 7014700 Tow ‘N Store Lock Kit
  3. BEST RECEIVER: Master Lock 2866DAT 1/2 in. and 5/8 in. Swivel Head
  4. BEST COUPLER: Tevlaphee Universal Trailer Ball Tow Hitch Lock
  5. BEST LATCH PIN: Master Lock 3-1/2″ Long Shackle x 9/32″ Diameter Pin
  6. BEST HITCH PIN: METOWARE Trailer Hitch Receiver Pin Lock
Best Trailer Lock Options

What to Consider When Choosing the Best Trailer Lock

Before choosing a lock for a trailer, first consider the type of lock, its material, the compatibility of the lock with the trailer hitch, and the level of security the lock will provide.


Trailer locks come in two main types based on their appearance and function: receiver and coupler trailer hitch locks.

  • Receiver-style trailer hitch locks are metal pins with one or two locking ends. They can be used as latch pinlocks or hitch pinlocks, depending on the part of the hitch that’s locked.

    • Latch pinlocks have a universal fit that measures about 9/32 inches in diameter. They slide through a hole in the trailer hitch latch to lock it in place. With the latch locked, the coupling can’t open. If the coupling is already secured to a towing hitch when the latch pinlock goes through the latch, then the trailer hitch will remain attached to the towing hitch until the lock is removed.
    • Hitch pinlocks, which typically come in ½- or ⅝-inch diameters, help secure the towing hitch to the vehicle or the trailer hitch to the trailer. With this type of lock, thieves can’t remove the entire hitch, connect their own vehicle, and tow away the trailer.
  • Coupler-style trailer hitch locks have a U shape that looks similar to a bike lock. These locks feature a ball-shaped top that fits into the tongue of the hitch and a bar that sits on top of the hitch that connects on both sides to the base of the lock. This design prevents a thief from connecting the hitch to a vehicle and stealing it from a driveway or work site. However, this lock doesn’t work when the trailer is connected to a vehicle.


When selecting a trailer lock, determine whether the lock is compatible with the trailer hitch.

  • Latch pinlocks generally measure 9/32 inches in diameter and have a universal fit with all standard trailer hitch latches.
  • Hitch pinlocks come in two main sizes that help determine which trailer hitch they can secure. Use ½-inch pins for class I and II trailer hitches with weight capacities up to 3,500 pounds. On class III and class IV trailer hitches that can tow 10,000 pounds or more, use a ⅝-inch pinlock.
  • Coupler-style locks typically come in a universal size that suits all standard coupler sizes, including 1 ⅞ inch, 2 inch, and 2 5/16 inch.


The lock’s material helps determine its durability and weather resistance. Lightweight, inexpensive trailer locks frequently are made of aluminum, which resists rust and corrosion but isn’t as durable as other materials.

Steel is often used to make trailer locks, including stainless steel and heavy-duty steel products with a zinc or chrome finish to help protect against rusting and corrosion. Steel locks are more durable than aluminum.


A trailer lock’s primary function is to protect the trailer from theft. Look for products with anti-lockpicking tumblers that use key cylinders with four or more pins. The lock’s complexity should deter most lockpicking attempts; however, thieves may resort to simply hitting the lock repeatedly with a hammer or crowbar.

If this type of damage is a risk, such as when the trailer must remain at a job site, find a lock with a protective cover to absorb impact damage. Heavy-duty locks commonly serve this purpose, though they cost more than a standard trailer hitch lock. Bright colors are another good security feature: A bright yellow lock may deter thieves from even attempting to steal a trailer.


If the trailer lock must accommodate more than one trailer, look for a versatile lock. Latch pinlocks and coupler-style locks are relatively universal, so they’re a good option for multiple trailer hitches.

However, hitch pinlocks are separated based on size, trailer hitch class, and towing weight capacity. Since ½-inch pins are intended only for class I and II trailer hitches with a maximum towing weight of 3,500 pounds, while ⅝-inch pins are made for class III and IV trailer hitches that can tow more than 10,000 pounds, check the specific product information for towing weight restrictions.

Our Top Picks

Keep tools, materials, and fastening gear safe in the trailer with one of the best trailer hitch locks. This list of top picks considers the type of trailer lock, compatibility, material, and overall quality to help shoppers find the best trailer lock to protect valuables from theft.

Best Overall

Trimax UMAX100 Premium Universal Dual Purpose Lock

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The heavy-duty Trimax UMAX100 universal trailer lock, which is manufactured with durable hardened steel, has a seven-pin key cylinder that resists lockpicking attempts. The steel core is covered in thick, ballistic-grade nylon that absorbs hammer blows and other impact damage while protecting the metal core from rusting and corrosion.

This coupler-style trailer hitch lock fits all standard trailer hitches and has a keyhole cover that slides up to prevent dirt, mud, and debris from clogging the tumbler. Most coupler-style locks have only one adjustable side, but this one has a dual-ratchet locking system. Users can customize the fit.

Best Bang For the Buck

Reese Towpower 7014700 Tow 'N Store Lock Kit

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This affordable Reese Towpower bundle of trailer hitch locks comes with a theft-deterrent bright yellow coupler-style trailer hitch with a universal fit for all standard trailer hitches. It also includes a padlock and receiver-style trailer hitch lock to secure the towing hitch to the vehicle or the trailer hitch to the trailer. The receiver-style hitch has a ½-inch pin for class I and II trailer hitches and a ⅝-inch pin for class III and IV trailer hitches.

Corrosion-resistant steel makes the locks more durable. The bundle comes with two keys, but one key opens all three locks so the other can serve as a backup. This bundle secures the entire hitch from vehicle to trailer.

Best Receiver

Master Lock 2866DAT 1/2 in. and 5/8 in. Swivel Head

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Receiver-style trailer locks must be the correct diameter to fit a specific class of trailer hitch. This lock from Master Lock contains both a ½-inch pin for class I and II hitches and a ⅝-inch pin for class III and IV hitches.

The receiver trailer hitch lock and pins are made of durable stainless steel, and the locking head has a snap-on cover to prevent dirt, grease, and moisture from entering the key cylinder. The lock comes with two keys. This product’s locking head rotates 360 degrees for easy access to the keyhole.

Best Coupler

Tevlaphee Universal Trailer Ball Tow Hitch Lock

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This durable heavy-duty steel coupler trailer lock from Tevlaphee has a universal size to fit most types of trailers and RVs. The ratcheting lock design has 11 different locking positions to help ensure the most secure fit over the trailer hitch. It comes with two identical keys.

The ball of this coupler-style lock slips under the tongue of the hitch, and a broad stainless steel bar goes over the top of the hitch and locks into the coupler lock base. This product comes in three bright colors: blue, red, and yellow.

Best Latch Pin

Master Lock 3-1/2u0022 Long Shackle x 9/32u0022 Diameter Pin

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This Master Lock latch pinlock slides through the latch to prevent removal of the trailer. This device locks the latch in place so that it can’t open the coupling to release the trailer hitch ball. If the trailer is not connected to a vehicle hitch, the latch pinlock prevents the coupling from opening.

The latch pin trailer lock comes with a pair of keys and has a snap-on plastic cover to protect the key cylinder from mud, dirt, and moisture. A 9/32-inch pin diameter is a universal fit for standard coupler latches. Its chrome plating helps prevent corrosion and rusting.

Best Hitch Pin

METOWARE Trailer Hitch Receiver Pin Lock

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It’s infuriating to lock the trailer with a coupler and a latch pinlock only to come back and find that a thief has removed the entire hitch to steal the trailer. Add one of these METOWARE hitch pinlocks to the trailer hitch to prevent this scenario and attach the second lock to the towing hitch to prevent thieves from removing it from the vehicle.

These hitch pinlocks are made of durable stainless steel, and each comes with a pair of keys for an always-available spare. The hitch pinlocks measure ⅝ inch in diameter, so they can secure class III and IV trailer hitches. The locking hitch pins are suitable replacements for standard hitch pins and boast a maximum towing capacity of 30,000 pounds. Rubber snap-on caps help prevent corrosion by protecting the keyholes from dirt, mud, and moisture.

FAQs About Trailer Locks

Trailer locks help prevent would-be thieves from stealing your trailer and its contents. Take a look below at some of the most commonly asked questions and their answers about the best trailer locks.

Q. How does a trailer hitch lock work?

Trailer hitch locks cover the trailer hitch ball with a coupler-style lock that prevents someone from attaching the trailer to a vehicle without removing the lock. A receiver-style trailer hitch lock inserts through the hitch to prevent thieves from disconnecting the trailer. To properly secure a trailer, experts advise using both styles of hitch lock.

Q. Are locking hitch pins safe?

Locking hitch pins are safe and typically rated for use in place of a standard hitch pin so that the trailer can stay fastened securely to the vehicle while being towed.

Q. How do you lock a trailer hitch?

It depends on the trailer lock. Coupler-style locks have a ball that fits into the trailer hitch tongue. A metal loop or bar fits over the hitch and slides down into the coupler lock where it’s secured with a key. Some coupler locks may have an opening for a separate padlock instead of a built-in lock. On these, simply open the padlock and remove it from the coupler trailer hitch lock. Receiver-style locks fit through the trailer hitch and lock on one side or both. This prevents removal of the entire hitch.

Q. How do you open a locked hitch?

Open a locked hitch with its key. Just put the key in the lock, turn it, then remove the bar or locking base, similar to a bike lock. It’s quick and easy, so you won’t need to worry about breaking out a lock pick set.


Timothy Dale Avatar

Timothy Dale

Contributing Writer

Timothy Dale is a home improvement writer who has been in the industry for several years. In his work for, he has written a number of how-to articles related to yard maintenance, vehicle repair, and home renovation, not to mention a wide variety of buying guides and articles on DIY projects. He always ensures readers get the information they need to tackle their next project.