New Hampshire trailer laws and regulations
New Hampshire trailer rules: title and brake thresholds at 3,000 lb, towing plates, mobile home speed cap, lighting and stopping distance requirements.
In New Hampshire, the 3,000 lb mark is the line for both titles and trailer brakes. Trailers at or under 3,000 lb gross weight skip the title requirement. Trailers over 3,000 lb need to be titled and need brakes that the driver can apply from the cab on all trailer wheels.
The state also runs a slightly unusual plate rule: any trailer being towed needs a copy of the tow vehicle’s licence plate affixed to it, so if multiple vehicles share a trailer, you need the right plate on for each tow.
Quick reference
| Item | New Hampshire rule |
|---|---|
| Title | Trailers over 3,000 lb GVW |
| Bill of sale | Required for trailers 3,000 lb or less |
| Trailer plate | Must match the current tow vehicle |
| Brakes | Trailers over 3,000 lb, all wheels, cab-operated |
| Max trailer length | 48 ft including bumpers |
| Max width | 102 in |
| Max height | 13 ft 6 in |
| Stopping distance | 30 ft from 20 mph (dry) |
| Mobile home tow speed cap | 45 mph |
Registration and titles
For a utility trailer or camper with a GVW of 3,000 lb or less, you need an original bill of sale. If the bill of sale doesn’t show a VIN, get the seller to complete a TDMV 19A VIN Verification Form, or take the seller’s existing NH registration as proof.
Trailers over 3,000 lb need a title. After applying, new titles typically arrive in 40 to 50 days.
Every trailer being towed has to display a copy of the tow vehicle’s licence plate. Legal towing plates can be made up with the tow vehicle’s number. If different vehicles tow the same trailer, the plate has to match the current tow vehicle.
General towing rules
Trailers and semi-trailers need safety chains or cables in addition to the primary coupling. Those chains have to be strong enough to take the full load.
Towing of a broken-down motor vehicle is restricted to professional tow operators. A non-professional can tow a disabled vehicle no more than one mile, and only to get it out of harm’s way, and the connection has to be such that nobody has to steer the disabled vehicle.
With limited exceptions (agricultural setups, mainly), no vehicle can tow more than two trailers at once.
Dimensions
The trailer body maxes out at 48 ft including bumpers. Width is 102 inches and height is 13 ft 6 in. New Hampshire doesn’t publish a single number for combination length.
Hitches and chains
The ball hitch has to be either bumper-mounted or frame-connected. Safety chains are required.
Lighting rules
- Stop lamps have to be operational at all times while towing.
- Directional signals are required on trailers built after January 1, 1952.
- After-dark towing needs a red tail light visible from at least 1,000 ft and a white licence plate light visible from 50 ft.
- Tail lamps mount between 20 and 72 inches above the road.
- Trailers over 3,000 lb need one amber reflector near the front and one red reflector near the rear, mounted 24 to 48 inches above the road.
Speed limits while towing
Posted limits apply. The one specific exception is mobile homes, where the tow speed limit is 45 mph.
Mirror rules
If your load blocks the rear view, you need a mirror or reflector that gives a clear view of the road behind. The general motor vehicle rule applies to towing.
Brake rules
Brakes have to be in good working order whenever you’re towing. The combined vehicle and trailer have to be able to come to a full stop from 20 mph in 30 ft on dry pavement. That’s the cited performance standard, and it’s how a stopping-distance test is set up if one is ordered.
In practice, for any trailer over 3,000 lb GVW, brakes on all wheels, controllable from the cab, are required to meet that standard with a typical tow vehicle.