Best Trailer Door Locks
Our top picks
Proven Industries Cargo Door Lock
Shrouded design hides the shackle.
About $164
Check price at Proven ↗AMPLock
Custom-fit range for many coupler types.
Check current price
Check price at AMPLock ↗Proven Industries Model 2516
Custom fit wraps the coupler, little room for tools.
About $250 (provenlocks.com list)
Check price at Proven ↗
Comparison
| Lock | Best for | Fits | Price (approx.) | |
|---|---|---|---|---|
| Proven Industries Cargo Door Lock | Best cargo door lock | Enclosed/cargo trailer doors (check model fit) | About $164 | Check price ↗ |
| AMPLock (coupler, gooseneck, kingpin, hitch, latch pin, door locks) | Best for barn-door and roll-up | 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 ↗ |
| Proven Industries Model 2516 | Pair with: coupler lock | Most 2-5/16 in trigger- and thumb-latch couplers | About $250 (provenlocks.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 Cargo Door Lock
Who it is for: Enclosed/cargo trailer owners.
- Shrouded design hides the shackle
- Keyed-alike option
- Check fit for your handle style
- Type: Cargo door lock
- Fits: Enclosed/cargo trailer doors (check model fit)
- Build: Aircraft-grade aluminum (per maker)
- Keyed alike: Yes
- Price: About $164
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 ↗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 ↗Door types
- Barn doors with cam bars: most common on cargo trailers; protect the handle and hasp.
- Ramp doors: secure both side latches.
- Roll-up doors: need a lock designed for the roll-up latch.
- Side (RV-style) doors: factory locks are often keyed the same across many trailers, so add a deadbolt or keyed-alike upgrade.
What to look for
- A shroud that hides the shackle from cutters.
- Fit to your handle style; check maker fit guides.
- Corrosion resistance and a weather cap.
- Keyed alike with your coupler lock.
How cargo trailers are usually broken into
Thieves go for the easiest point: a padlock hanging on an exposed hasp, which can be cut with bolt cutters in seconds. Other weak points are factory side-door locks that use common keys, and ramp-door latches with no lock at all. A shrouded lock that hides the shackle removes the quick win.
Choosing by door
| Door | What to buy | Check before buying |
|---|---|---|
| Barn doors (cam bar) | Shrouded cam bar / door lock (e.g. Proven cargo door lock, AMPLock barn-door models) | Handle style and spacing |
| Rear ramp door | Lockable ramp latches on both sides | Latch type and mounting holes |
| Roll-up door | Roll-up specific lock (AMPLock lists roll-up models) | Latch shape |
| Side entry door | Upgraded lock cylinder or added deadbolt | Door thickness, existing cutouts |
Extra steps for valuable cargo
- Park with the rear doors against a wall or another trailer.
- Use a coupler lock so the whole trailer cannot be towed away to be opened elsewhere.
- Keep an inventory with serial numbers and photos for insurance.
- Consider a hidden GPS tracker inside the trailer.
Our pick
Proven Industries Cargo Door Lock: best cargo door lock. Enclosed/cargo trailer owners. If budget matters more, see the other picks above.
Check price at Proven ↗FAQs
- Are factory trailer door locks secure?
- Many use common keys and light hasps. An aftermarket shrouded lock is a meaningful upgrade.
- What is a cam bar lock?
- A lock that secures the vertical cam bar handle on barn-style trailer doors.
- Can I key my door lock alike with my coupler lock?
- Often yes within the same brand. Proven offers keyed-alike ordering across its range.