South Carolina trailer laws and regulations

South Carolina requires every trailer driven on public highways to be titled, registered, and plated. The brake threshold is 3,000 lbs, the max trailer width is 102 inches, and the max combined height is 13 ft 6 in. House trailers cannot be towed faster than 45 mph.

Quick reference

South Carolina Code Title 56 (Motor Vehicles) is the source. The DMV handles trailer titling and registration.

Registration and title

Every motor vehicle, trailer, semi trailer, and pole trailer driven, operated, or moved on South Carolina highways must be registered, licensed, and display a plate on the back. That includes utility trailers, boat trailers, and travel trailers.

Trailers do not require their own insurance, and they are not automatically covered by your auto policy. If you are towing anything valuable, a separate trailer insurance rider is worth pricing.

Letting your registration lapse creates back-fee headaches when you try to re-register, so renew on time even if you only use the trailer a few times a year.

Dimensions

• Max trailer length: 48 ft
• Max trailer width: 102 in (extra width is allowed if it comes from an appurtenance like a mirror or load-securing device)
• Max combined height: 13 ft 6 in
• Combined vehicle plus trailer length: not specified at the state level

If you are running anything wider, taller, or longer than the limits above, you need an oversize/overweight permit from the South Carolina Department of Transportation.

Hitch, drawbar, and safety chain rules

The drawbar, chain, rope, cable, or any other connection between the tow vehicle and trailer cannot exceed 15 ft. It also has to be strong enough to support the full towed weight.

If you are using a chain, rope, or cable as the primary connection, a white flag or cloth at least 12 inches square must be attached to it so other drivers can see the link.

Lighting

All trailers must have:

• Tail lights
• Brake lights
• Turn signals
• License plate light
• Reflectors

If your tow vehicle is a 2021 to 2026 Ford F-150 or 2022 to 2026 Super Duty, F-Series Ranger, Maverick, Expedition, Transit, or Lincoln Navigator, check whether recall 26C10 (NHTSA 26V104000) applies. The Integrated Trailer Module software fault covered by that recall affects trailer light and brake function. Ford pushed an OTA fix in March 2026, but vehicles that have not received it can still have intermittent trailer-light problems.

Speed limits while towing

There is no special towing speed in South Carolina general traffic. Two exceptions:

• House trailers: 45 mph maximum
• Manufactured, modular, or mobile homes: 10 mph below the posted limit

If your trailer is swaying, an officer can pull you over even when you are under the posted limit. The standard is whether the combination is a hazard, not just whether the number on the speedometer is legal.

Mirrors

South Carolina does not specify the exact mirror setup, but the driver must be able to see at least 200 ft of road behind the vehicle. If your trailer blocks the interior mirror, you need side mirrors (or mirror extenders) that meet that 200 ft requirement.

Brakes

The basic rules in S.C. Code §56-5-4910 and related sections:

• Service brakes must be effective and able to stop and hold the rig on any grade on which it is operated.
• Vehicles made after June 7, 1949 need brakes on all wheels, with one exception: trailers and semi trailers weighing less than 3,001 lbs are exempt as long as the trailer’s wheel weight does not exceed 40% of the tow vehicle’s gross weight when connected.
• Any vehicle made after July 1, 1964 that is used to tow must be able to demonstrate that the service brakes alone can stop the rig.
• All brakes on the combination must be operable by a single device in the cab.

In practice: a single-axle trailer over 3,000 lbs needs working brakes that the driver can apply from the cab. Most aftermarket electric brake controllers (Tekonsha P3, Redarc Tow-Pro, etc.) meet this without modification.