South Carolina IFTA Fuel Tax Compliance and Filing Guide

The International Fuel Tax Agreement (IFTA) is a reciprocal agreement between 48 U.S. states and 10 Canadian provinces to simplify the reporting of fuel used by interstate motor carriers. In South Carolina, the program is administered by the South Carolina Department of Revenue (SCDOR). Carriers are qualified if they operate a motor vehicle used, designed, or maintained for the transportation of persons or property and have two axles and a gross vehicle weight exceeding 26,000 pounds, or have three or more axles regardless of weight, or are used in combination when the weight of such combination exceeds 26,000 pounds. This state-specific system allows carriers to file one tax return to the SCDOR, which then handles the distribution of funds to other jurisdictions. Effective management of South Carolina IFTA obligations requires precise documentation of every mile driven and every gallon purchased. DispatchTool simplifies this by automating the collection of GPS-based trip data and fuel purchase records, ensuring your quarterly reports reflect exact mileage across state lines. This reduces the risk of manual entry errors that often lead to SCDOR audits or penalties. By integrating your ELD data directly into a unified platform, you can generate the necessary summaries for your SCTaxWay filings in minutes. Create a DispatchTool account to streamline your IFTA record-keeping and fleet documentation.

SCDOR Registration and Licensing Requirements

To register for an IFTA license in South Carolina, a carrier must have an established place of business in the state, maintain operational control from a South Carolina location, and have records available for audit in the state. New applicants must complete Form IFTA-1 (Application for IFTA License) and submit it to the SCDOR. There is no fee for the initial South Carolina IFTA license or the two required vehicle decals. However, carriers must be in good standing with all state tax liabilities before a license is issued. Once approved, the license is valid for one calendar year, expiring on December 31, and must be renewed annually through the MyDORWAY portal to ensure continuous legal operation.

Quarterly Filing Deadlines and Penalties

South Carolina requires IFTA tax returns to be filed quarterly. The deadlines are strictly enforced: Q1 (Jan-Mar) is due April 30; Q2 (Apr-Jun) is due July 31; Q3 (Jul-Sep) is due October 31; and Q4 (Oct-Dec) is due January 31. If the due date falls on a weekend or state holiday, the return is due the next business day. Failure to file by the deadline results in a penalty of $50.00 or 10% of the net tax due, whichever is greater. Furthermore, interest is charged on all late payments at a rate of 1% per month, calculated from the date the tax was originally due until the date of payment. All filings in South Carolina must be submitted electronically via the MyDORWAY system.

Fuel Tax Rates and Surcharge Calculations

As of 2024, the South Carolina motor fuel tax rate is $0.28 per gallon. This rate has seen incremental annual increases of $0.02 per year as part of the South Carolina Infrastructure and Economic Development Reform Act. When filing your IFTA return, you must account for the specific tax rates of every jurisdiction your vehicles traveled through. For example, if a vehicle travels through North Carolina, the rate is $0.404 per gallon, and in Georgia, it is $0.323 for diesel. The MyDORWAY system automatically calculates the net tax due or credit based on the total gallons purchased in South Carolina versus the total miles driven in each member jurisdiction.

Record Retention and Audit Standards

The SCDOR mandates that carriers maintain detailed records for a period of four years from the filing date. These records must include Individual Vehicle Mileage Records (IVMRs) that document the date of each trip, trip origin and destination, routes of travel, beginning and ending odometer readings, and total distance traveled in each jurisdiction. Fuel records must include original receipts or invoices showing the date of purchase, name and address of the seller, number of gallons purchased, fuel type, and the unit number of the vehicle. Summaries of these records must be compiled monthly and quarterly to support the figures reported on the IFTA tax return. Digital records are acceptable provided they are accessible and readable during an audit.

South Carolina Intrastate vs. Interstate Travel

Carriers that operate exclusively within the borders of South Carolina are not required to participate in IFTA. These intrastate carriers pay the state fuel tax at the pump and do not file quarterly returns. However, the moment a vehicle crosses the state line into North Carolina or Georgia, it becomes subject to IFTA regulations if it meets the weight thresholds. If an interstate carrier occasionally operates a vehicle that does not have an IFTA decal, they must purchase a South Carolina Trip Permit. This permit costs $15.00 and is valid for 72 hours, allowing the vehicle to operate legally without a permanent IFTA license, though this is often more expensive for regular operations than maintaining a standard license.

Managing Credits and Refunds

If the tax paid at the pump in South Carolina and other jurisdictions exceeds the total tax liability for the miles driven, a credit is generated on the quarterly return. Credits can be applied to future tax liabilities in subsequent quarters. If a carrier wishes to receive a cash refund for the overpayment, they must specifically request it on the MyDORWAY filing. Refunds are generally processed within 90 days of the request, provided there are no outstanding tax debts in other categories. It is important to note that credits older than eight quarters (two years) will expire and cannot be used or refunded, according to SCDOR guidelines.

Sources

South Carolina Department of Revenue (2024) — https://dor.sc.gov/tax/ifta IFTA, Inc. South Carolina Profile (2024) — https://www.iftach.org South Carolina Legislature - Title 12, Chapter 28 (2023) — https://www.scstatehouse.gov/code/t12c028.php

Frequently asked

What is the weight threshold for IFTA in South Carolina?

A vehicle must be registered for IFTA if it has a gross vehicle weight or registered gross vehicle weight exceeding 26,000 pounds, or has three or more axles regardless of weight.

How much does it cost to get IFTA decals in South Carolina?

South Carolina does not charge a fee for the annual IFTA license or the two decals provided for each qualified motor vehicle.

Can I file my South Carolina IFTA return by mail?

No, the South Carolina Department of Revenue requires all IFTA returns to be filed electronically through the MyDORWAY online portal.

What is the penalty for late IFTA filing in SC?

The penalty is $50.00 or 10% of the total tax due, whichever is greater, plus monthly interest of 1% on the unpaid balance.

Do I need IFTA if I only drive in South Carolina?

No, if you never leave the state of South Carolina, you are an intrastate carrier and do not need to register for IFTA; you simply pay tax at the pump.