Quarterly Tax Returns

You must file an International Fuel Tax Agreement (IFTA) Return (SCDMV Form IFTA-3) with Motor Carrier Services (MCS) that includes your travel and fuel purchases for the quarter. This return must include the total miles traveled and the total gallons of fuel purchased during the reporting period.

The quarterly tax return indicates the tax or refund due for each member jurisdiction. You can file IFTA quarterly tax returns online if you have access to the MCS system.

All IFTA tax returns are to be reported in United States measurements. If you have Canadian travel and fuel purchases, the conversion rates are:

• 1 liter = .2642 gallons
• 1 kilometer = .62137 miles
• All numbers must be rounded to the nearest whole gallon or mile.
• Tax returns are due on the last day of the month immediately following the close of the quarter for which the return is being filed.

Return Due Dates 

Due Date Guidelines 

• Your return must be postmarked and in a PAID status or hand delivered to MCS, by the due date.
• If the due date is Saturday, Sunday, or a legal holiday, your return is due the next business day.

You may visit one of the 8 branch offices or mail your IFTA tax quarterly return to:

SCDMV
Motor Carrier Services 
PO Box 1498
Blythewood, SC 29016-0027 

Penalty and Interest Provisions

You may be penalized if you do not file a return, file a return late, file an amended return, or fail to pay the total amount of taxes you owe. 

The penalty will be $50 or 10% of the net tax due, whichever is greater. The interest rate is an annual rate of 2% above the underpayment rate established by the IRS. For example, if the IRS underpayment rate equals 3%, the International Fuel Tax Agreement annual interest rate equals 5%. Interest accrues monthly at 1/12 the annual rate.

Amended Returns

You should file an amended return when you determine an error was made on the original return. The SCDMV may request amended returns on an as-needed basis. A penalty and interest fee will be added to amended returns in the same way they're added to late returns.

Failure to File Returns

When you fail, neglect, or refuse to file an IFTA tax return, the SCDMV may assess a penalty based on the best information available, including the licensee's filing history. You will owe estimated tax, penalty, and interest. You must prove the assessment is incorrect.

Failing to file quarterly tax returns will result in the suspension or revocation of your IFTA license and decals.

Tax Exemptions

IFTA recognizes that some jurisdictions allow for tax-exempt fuel and tax-exempt miles. You must get a refund for tax-exempt fuel from the state you paid the tax in. It is your responsibility to keep correct records to support the exemption you claimed.
 
Tax-exempt miles must be included on your IFTA Return (SCDMV Form IFTA-3) in the total miles operated during the quarter. The miles are deducted from the total miles for each jurisdiction (Column B), and the difference is reported as taxable miles (Column C). If you deduct tax-exempt miles on your quarterly tax return, it is your responsibility to maintain proper documentation for those exemptions. 
 
Miles operated under a fuel trip permit are not taxable, but they must be included in the total miles for the quarter and in the total miles for the jurisdiction in which they were traveled.

Tax Refunds

A refund may be claimed on the IFTA tax return if you overpaid taxes during a reporting period. A refund will be issued for overpaid tax amounts of $5 or more. 

A refund may be denied if there are any outstanding debts owed to the department.