Best Trailer Locks for 2026
Our top picks
Proven Industries Model 2516
Custom fit wraps the coupler, little room for tools.
About $250 (provenlocks.com list)
Check price at Proven ↗AMPLock
Custom-fit range for many coupler types.
Check current price
Check price at AMPLock ↗Trimax UMAX100
Hardened steel with nylon housing.
About $130 (trimaxlocks.com list)
Check price at Trimax ↗
Comparison
| Lock | Best for | Fits | Price (approx.) | |
|---|---|---|---|---|
| Proven Industries Model 2516 | Best overall coupler lock (2-5/16 in) | Most 2-5/16 in trigger- and thumb-latch couplers | About $250 (provenlocks.com list) | Check price ↗ |
| AMPLock (coupler, gooseneck, kingpin, hitch, latch pin, door locks) | Best custom-fit alternative | Coupler (boat, RV, cargo), gooseneck (Bulldog, Atwood), kingpin, hitch 1-1/4 to 3 in, latch pin, barn/roll-up door | Check current price | Check price ↗ |
| Trimax UMAX100 | Best universal coupler lock | Most 1-7/8 in, 2 in and 2-5/16 in couplers | About $130 (trimaxlocks.com list) | Check price ↗ |
| Master Lock 389DAT | Best budget coupler lock | Most 1-7/8 in, 2 in and 2-5/16 in couplers incl. surge-brake, rolled-lip, UFP | About $36 (masterlock.com list) | Check price ↗ |
| Master Lock 2866DAT | Best hitch pin lock | 1/2 in and 5/8 in receivers; 2-3/4 in usable pin length | About $19 (masterlock.com list) | Check price ↗ |
| Trimax TCL65 | Best wheel lock for storage | Tires roughly 6 to 10.5 in wide span, 7.25 in reach | About $163 (trimaxlocks.com list) | Check price ↗ |
How we chose: picks are based on published specifications, materials, fit charts, manufacturer information and patterns in owner reports. We have not lab-tested these locks. Prices are approximate list prices seen on maker sites in October 2026 and change often.
Our picks in detail
Proven Industries Model 2516
Who it is for: Owners of valuable 2-5/16 in trailers stored unattended.
- Custom fit wraps the coupler, little room for tools
- 1/4 in steel, tubular key
- Keyed-alike option across the range
- Can capture most safety chain hooks
- Expensive
- Must match your exact coupler model
- Heavy
- Type: Coupler lock (custom-fit)
- Fits: Most 2-5/16 in trigger- and thumb-latch couplers
- Build: 1/4 in steel, black powder coat, puck lock, 7-pin tubular key
- Keyed alike: Yes (keyed-alike option across Proven line)
- Price: About $250 (provenlocks.com list)
Can secure most 5/16 in safety chain hooks per maker; check the fit index for your coupler.
Check price at Proven ↗AMPLock (coupler, gooseneck, kingpin, hitch, latch pin, door locks)
Who it is for: Owners who want custom-fit security and a fit-finder.
- Custom-fit range for many coupler types
- 5-year warranty with registration
- Fit quiz on maker site
- Prices not confirmed on our check
- Heavy
- Type: Custom-fit lock range
- Fits: Coupler (boat, RV, cargo), gooseneck (Bulldog, Atwood), kingpin, hitch 1-1/4 to 3 in, latch pin, barn/roll-up door
- Build: Heavy-duty steel, custom-fit; fit quiz on site
- Keyed alike: Check per model
- Price: Check current price
5-year warranty with registration (per maker).
Check price at AMPLock ↗Trimax UMAX100
Who it is for: Owners wanting more security than budget locks without custom-fit prices.
- Hardened steel with nylon housing
- Fits 1-7/8, 2 and 2-5/16 in
- Keys alike with other Trimax locks
- Universal fit, not glove-tight
- Bulkier than budget locks
- Type: Universal coupler lock
- Fits: Most 1-7/8 in, 2 in and 2-5/16 in couplers
- Build: Solid hardened steel, ballistic nylon housing, 9/16 in shackle
- Keyed alike: Keys alike to other Trimax locks (per catalog)
- Price: About $130 (trimaxlocks.com list)
Master Lock 389DAT
Who it is for: Boat and utility trailers on a budget.
- Low price
- Wide fit incl. surge-brake couplers
- Bright red is a visible deterrent
- Cannot be keyed alike
- Universal fit leaves room to pry
- Type: Universal coupler (ball) lock
- Fits: Most 1-7/8 in, 2 in and 2-5/16 in couplers incl. surge-brake, rolled-lip, UFP
- Build: Red powder-coated steel, wafer tumbler, keyway cover
- Keyed alike: No (cannot be keyed alike)
- Price: About $36 (masterlock.com list)
Bright red as a visual deterrent.
Check price at Master Lock ↗Master Lock 2866DAT
Who it is for: Most trucks with 1-1/4 or 2 in receivers.
- Fits 1/2 and 5/8 in receivers
- Rated up to Class III/IV, 10,000 lb (5/8 in)
- Weather seal and cap
- Only protects the hitch, not an unhitched trailer
- 2-3/4 in span too short for some receivers
- Type: Receiver hitch pin lock
- Fits: 1/2 in and 5/8 in receivers; 2-3/4 in usable pin length
- Build: Swivel head, push-to-lock, weather seal and cap, 4-pin cylinder
- Keyed alike: K1 key blank
- Price: About $19 (masterlock.com list)
5/8 in pin rated Class III/IV, 10,000 lb; 1/2 in Class I/II, 3,500 lb.
Check price at Master Lock ↗Trimax TCL65
Who it is for: Storage of boat, utility and camper trailers.
- Doubles as a wheel chock
- Adjustable span 6 to 10.5 in
- Rubber-coated arms protect rims
- Must fit your tire width and fender clearance
- Slower to fit than a coupler lock
- Type: Wheel chock lock
- Fits: Tires roughly 6 to 10.5 in wide span, 7.25 in reach
- Build: Heavy-gauge powder-coated steel, rubber-coated arms, built-in chock
- Keyed alike: -
- Price: About $163 (trimaxlocks.com list)
The three kinds of trailer lock
Coupler (ball) locks fill or cover the coupler so it cannot drop onto a hitch ball. This is the lock that stops a thief backing up and towing away an unhitched trailer.
Hitch pin (receiver) locks replace the plain pin and clip on a receiver hitch, so the ball mount or the whole trailer cannot be unpinned from your truck while parked.
Wheel locks and boots clamp a tire so the trailer cannot roll. They are slower to fit, which is why they suit storage more than quick stops.
See our guides to coupler locks, hitch locks and wheel locks for deeper comparisons.
How to choose
- Ball size: read the size stamped on your coupler (1-7/8 in, 2 in or 2-5/16 in). Custom-fit locks are sold per size; universal locks cover all three but fit looser.
- Coupler type: trigger latch, thumb latch, lever/latch style (Atwood-type), surge-brake (common on boat trailers) or cast-steel. Custom-fit makers publish fit charts; check yours before buying.
- Material and coverage: thick steel that wraps the whole coupler leaves less room for pry bars and cutters than a small ball plug with an exposed shackle.
- Lock cylinder: tubular and disc cylinders resist picking better than basic wafer locks. Look for a keyway cover so dirt and road salt stay out.
- Keyed alike: if you also lock the hitch pin, spare tire or doors, a keyed-alike set means one key for everything.
- Weather: powder coat, stainless pins and sealed keyholes matter if the trailer sits outside or near salt water.
Universal vs custom-fit
Universal locks (Master Lock 379ATPY and 389DAT, Trimax UMAX100) fit most 1-7/8, 2 and 2-5/16 in couplers, cost roughly $35 to $130, and are easy to move between trailers. Custom-fit locks (Proven Industries, AMPLock) are made for a specific coupler shape, so they wrap it tightly and leave fewer gaps for tools. They cost more, roughly $150 to $350, and you must buy the right model.
A practical rule: if the trailer or its load is worth more than a few thousand dollars, or it sits unattended in storage, the tighter fit of a custom lock is usually worth it.
Layer your security
- Coupler lock whenever unhitched.
- Locking hitch pin whenever hitched and parked.
- Wheel lock or boot for storage longer than a few days.
- A hidden GPS tracker if the trailer or cargo is valuable.
- Park with the coupler facing a wall or blocked by another vehicle.
Our pick
Proven Industries Model 2516: best overall coupler lock (2-5/16 in). Owners of valuable 2-5/16 in trailers stored unattended. If budget matters more, see the other picks above.
Check price at Proven ↗FAQs
- What is the most secure trailer lock?
- A custom-fit coupler lock made of thick steel that encloses the whole coupler, combined with a second lock type such as a wheel lock. No lock is theft-proof; the goal is to make your trailer slower and noisier to steal than the one next to it.
- Do trailer locks really prevent theft?
- They deter most opportunistic thieves, who look for unlocked trailers they can hitch in seconds. A determined thief with power tools can defeat any lock, which is why layering two lock types helps.
- What size trailer lock do I need?
- Match the ball size stamped on your coupler: 1-7/8, 2 or 2-5/16 in. Universal locks cover all three; custom-fit locks are sold per size and coupler style.
- Are universal coupler locks any good?
- They are a solid budget option and fit most couplers, but their looser fit leaves more room for prying than a custom-fit lock.