Does a South Carolina truck need a USDOT number for in-state work?

Yes. South Carolina is on FMCSA's list of states that require in-state carriers to have a USDOT number. Its safety rules apply from 26,001 lb; we found no state source giving a separate line for the number itself, so ask SCDPS if your trucks are lighter.

Checked against South Carolina’s official sources in September 2026.

The rule in South Carolina

Who it covers: Intrastate commercial motor vehicles and their drivers (for-hire and private) at or above 26,001 lb, plus any vehicle carrying placarded hazmat or designed for 16+ passengers. Separately, intrastate for-hire property carriers need an SCDMV Certificate of Compliance (household goods, passenger and hazardous-waste carriers are handled differently).

The weight line: In-state trucks at 26,001 lb or more (rated or actual, single or combination) must follow the federal motor carrier safety rules; lighter trucks are exempt unless they carry placarded hazmat or 16+ passengers. No South Carolina source found that states the weight line for the USDOT number itself.

Exemptions the state lists:

CMVs operating below 26,001 lb are exempt from the FMCSR requirements of S.C. Code § 56-5-4240(A), unless placarded hazmat or designed for 16+ passengers
Farm trucks operating solely in intrastate commerce need not be marked with the owner's name (S.C. Code § 56-5-4150(A))

“Apart from federal regulations, some states require their intrastate commercial motor vehicle registrants to obtain a USDOT Number. These states include: ... South Carolina” source

“a commercial motor vehicle (CMV) and its driver operating in intrastate commerce with a gross vehicle weight (GVW), gross vehicle weight rating (GVWR), gross combination weight (GCW), and gross combination weight rating (GCWR) equal to or exceeding 26,001 pounds must meet the requirements of the Federal Motor Carrier Safety Regulations” source

The rule: S.C. Code § 56-5-4240 (intrastate FMCSR applicability at 26,001 lb); S.C. Code Regs. 38-424 (adoption of 49 CFR). No South Carolina statute or rule found that itself requires an intrastate USDOT number.

Who to ask: South Carolina Department of Public Safety, State Transport Police (safety enforcement); SCDMV Motor Carrier Services (credentials, Certificate of Compliance)

Safety rules for in-state trucks

South Carolina applies 49 CFR Parts 382, 383, 385, 387 and 390-399 (and the hazmat rules) to interstate and intrastate carriers, including private carriers, except where they conflict with state law; intrastate drivers may be 18. (S.C. Code Regs. 38-424; S.C. Code § 56-5-4240)

Intrastate drivers may be 18 instead of 21.
State hours-of-service limits for intrastate drivers: 12 hours driving after 8 off, 16 on duty, 70/7 and 80/8.
Private trucks of 26,001 lb or more, and all for-hire trucks, must show the owner's or lessor's name on the side.

The federal lines, which apply in South Carolina too

10,001 lb and interstate commerce: a USDOT number, a medical card, a driver qualification file, the hours-of-service rules and daily inspections (49 CFR 390.5).
26,001 lb: a CDL, for a single vehicle or a combination towing more than 10,000 lb (383.5). The CDL rules cover in-state driving as well (383.3), and drug and alcohol testing follows the CDL (382.103).

Check your own truck and trailer

Questions

Does South Carolina require a USDOT number for intrastate trucks?

What is the CDL weight in South Carolina?

The same as everywhere: 26,001 lb for a single vehicle, or a combination of 26,001 lb towing more than 10,000 lb. The federal CDL rules apply to in-state driving too (49 CFR 383.3), and drug and alcohol testing follows the CDL (382.103).

Who administers the rule in South Carolina?

South Carolina Department of Public Safety, State Transport Police (safety enforcement); SCDMV Motor Carrier Services (credentials, Certificate of Compliance).

What we could not confirm

We found no South Carolina statute, rule or agency page that gives the weight line for the USDOT number itself; 26,001 lb is the line for the state's safety rules. A 2010 state FAQ on in-state DOT numbers could not be opened.

Sources

General information, not legal advice. It summarises South Carolina’s published rules as read in September 2026; confirm with the South Carolina Department of Public Safety or FMCSA.