IFTA Tax Rates in South Carolina (2026)

Key numbers at a glance

IFTA tax rates in South Carolina

South Carolina's IFTA rate is $0.28 per gallon on gasoline and diesel — the motor fuel user fee, shown at 28.0 cents in the Q4 2026 IFTA Inc. matrix and administered by the SC Department of Revenue. Broad comparison tables that stack inspection and environmental fees on top show roughly 28.75 cents combined at the pump — the Tax Foundation's July 2026 figure — but the matrix rate is what your return settles at. Rates below are as of Q4 2026 — confirm the current official IFTA matrix before filing.

The structure is simple by design: the 2017 roads law raised the user fee 2 cents each July 1 until it reached the 28-cent cap, where it has sat since 2022. One flat rate, both fuels, no surcharge, no indexing — the SC line of your IFTA return has been stable for years. The exception is 2026 itself: SCDOR notices in the fall described a temporary suspension of the motor fuel tax running into late November 2026, part of the same wave of state gas tax holidays that hit North Carolina and Ohio. If you ran SC miles in that window, verify with your base state exactly which rate applies to those miles on the Q4 return.

The line that jumps out is North Carolina at 41 cents — 13 cents more per gallon than SC on both fuels. On a 150-gallon fill, that is $19.50 of positioning value for choosing Florence over a stop a few miles up I-95 in the Tar Heel State.

How South Carolina IFTA affects your filings

The filing math is friendly. At 6.5 MPG, 1,000 South Carolina miles — roughly a full I-95 transit of the state — burns about 153.8 gallons and generates roughly $43.06 of SC fuel tax at 28 cents. Fuel bought in South Carolina pre-pays that amount gallon for gallon, so SC-heavy carriers who fuel in-state routinely show a wash or a small credit on that line. Test your own lane mix with the IFTA calculator before each quarter closes.

The decision point is the direction of your loads. South Carolina is a good state to buy in relative to the Southeast (28 cents beats North Carolina's 41), but a poor state to stock up in before running the Northeast — gallons bought at 28 cents and burned in Pennsylvania at 74.1 cents owe the full 46.1-cent difference per gallon. On 150 gallons that is $69.15 of avoidable tax due. The rule is unchanged from every other state: buy where the rate is high, burn where it is low, and always compare pump price minus tax rather than the number on the sign.

Bookkeeping closes the loop. Keep SC receipts matched to per-state miles out of the ELD, note the exact dates of any miles driven during the fall 2026 suspension window, and refresh the matrix each quarter rather than trusting last quarter's PDF. A late return costs $50–$100 plus interest, and repeated misses can suspend the license that keeps you legal interstate. Price your fuel surcharge off the states you actually run, not the national average, and keep the IFTA rates by state hub bookmarked for the other 47 jurisdictions on the map.