Trailer Latch Locks
Our top picks
AMPLock
Custom-fit range for many coupler types.
Check current price
Check price at AMPLock ↗Master Lock 389DAT
Low price.
About $36 (masterlock.com list)
Check price at Master Lock ↗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.) | |
|---|---|---|---|---|
| AMPLock (coupler, gooseneck, kingpin, hitch, latch pin, door locks) | Dedicated latch pin locks | 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 ↗ |
| Master Lock 389DAT | Upgrade: 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 ↗ |
| Proven Industries Model 2516 | Upgrade: custom 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
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 ↗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 ↗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 ↗When a latch lock makes sense
- Hitched and parked for a short stop (fuel, food, campsite).
- To stop pranksters releasing the latch.
- As one layer with a hitch pin lock.
Choosing one
- Measure the latch hole; most take a 1/4 in shackle or pin.
- Use a weatherproof or marine padlock if the trailer gets wet.
- Keyed-alike with your hitch pin lock if possible.
Limits
A thin shackle cuts easily. Treat latch locks as a convenience, not real theft protection.
Latch lock vs coupler lock vs hitch pin lock
| Lock | Protects against | Typical cost |
|---|---|---|
| Latch lock / padlock | Someone opening the latch and unhitching your trailer from your vehicle | Low |
| Hitch pin lock | Someone removing the ball mount (and trailer) from your receiver | About $19 and up (e.g. Master Lock 2866DAT) |
| Coupler lock | Someone hitching your unhitched trailer to their vehicle | About $36 to $300+ |
For a hitched trailer parked at a store or campsite, the latch lock plus hitch pin lock combination covers both release points. For an unhitched trailer, only a coupler or wheel lock helps.
Fitting tips
- Close the latch fully on the ball before inserting the lock, then tug the coupler upward to confirm it is seated.
- Use a padlock with a short shackle so there is little room for a cutter.
- Choose stainless or brass bodies for boat trailers; plain steel padlocks rust quickly.
- Keep a spare key in the tow vehicle, not on the trailer.
Do not confuse with a safety pin
Many couplers ship with a plain safety pin or clip in the latch hole. Its job is to stop the latch vibrating open while towing. A latch lock does the same job and adds a lock, so check it is rated or suitable for towing use if you leave it in while driving.
Our pick
AMPLock: dedicated latch pin locks. Owners who want custom-fit security and a fit-finder. If budget matters more, see the other picks above.
Check price at AMPLock ↗FAQs
- What size padlock fits a trailer latch?
- Most coupler latch holes take about a 1/4 in shackle; measure yours.
- Does a latch lock stop theft?
- Only from your hitched vehicle. An unhitched trailer needs a coupler or wheel lock.
- Can I tow with a latch lock fitted?
- Many owners do, as it replaces the safety pin. Make sure it fully closes the latch and will not vibrate loose.