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.

You must file a return even if the you do not drive or buy any fuel during the quarter. These are called "no operations" returnsThe quarterly tax return indicates the tax or refund due for each member jurisdiction. You will receive an email notification from MCS 30 days before your quarterly tax return is due. You can renew the quarterly tax returns online if you have access to the MCS system.

Login to Motor Carrier Services
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 

 Reporting Quarter Due Date
 January 1 - March 31 April 30
 April 1 - June 30 July 31
 July 1 - September 30 October 31
 October 1 - December 31 January 31

Due Date Guidelines 

  • Your return must be postmarked or hand delivered to MCS by the due date.
  • If you owe taxes, you must pay them by the due date. 
  • If the due date is Saturday, Sunday, or a legal holiday, your return is due the next business day.

If you're mailing your return, use the address below:

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

If you're turning them in in person, deliver the return to the address below:

SCDMV
Motor Carrier Services  
10311 Wilson Blvd.
Blythewood, SC 29016-0027 


Penalty and Interest Provisions

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, you may be penalized.

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

The International Fuel Tax Agreement (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 International Fuel Tax Agreement (IFTA) tax return if you overpaid taxes during a reporting period. If your refund is more than $5, you will receive it.

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