South Carolina CDL Study Guide
The South Carolina Department of Motor Vehicles issues Commercial Driver Licenses. SCDMV publishes the SC Commercial Driver License Manual (March 2025) on dmv.sc.gov. Applicants take knowledge tests and then a skills test at SCDMV CDL testing locations.
Key South Carolina numbers
- Minimum age (intrastate): 18
- Minimum age (interstate or hazmat): 21
- CLP hold before skills test: at least 14 days
- General Knowledge passing score: 80%
- General Knowledge test: ~50 questions
- Air Brakes test: ~25 questions (required if your vehicle has air brakes)
- Combination Vehicles test: ~20 questions (required for Class A)
Topics on the South Carolina General Knowledge test
- Vehicle inspection (pre-trip, en-route, post-trip)
- Driving safely (speed management, space management, hazard perception)
- Transporting cargo safely
- Air brakes (if your vehicle is air-braked)
- Combination vehicles (Class A)
If you fail a test
If you fail any portion of the skills test, the retest fee is $25 per attempt. SCDMV scheduling rules apply. Knowledge tests can also be retaken after paying the $2 per-test fee.
Frequently asked questions
What is the minimum age for a South Carolina CDL?
18 for intrastate driving and 21 for interstate driving or hazardous materials.
How long must I hold a SC CLP before the skills test?
At least 14 days from the date the CLP was issued.
How much does a South Carolina CDL cost?
$15 application + $2 per knowledge test + $2.50 CLP, then $2.50 per year for the CDL (about $20 for 8 years). Skills retest is $25.
Does South Carolina require ELDT?
Yes. Anyone who got a CLP after February 7, 2022 must complete FMCSA-approved ELDT before the skills test.
What is on the SC CDL General Knowledge test?
50 multiple-choice questions. You need 80% (40 correct) to pass.
Where is the official SC CDL Manual?
On the SCDMV website at dmv.sc.gov/sites/scdmv/files/media/Files/CDL-Manual.pdf (March 2025 version).
Free practice
Start a South Carolina General Knowledge quiz →
Sources: SCDMV Commercial Licenses SCDMV Getting Your First CDL SC CDL Manual PDF (March 2025) SCDMV CDL Testing