Connecticut IFTA Compliance and Reporting Guide

The International Fuel Tax Agreement (IFTA) is a tax collection agreement for fuel used by heavy commercial vehicles traveling through multiple jurisdictions. In Connecticut, the Department of Revenue Services (DRS) manages the registration and quarterly tax returns for carriers based in the state. A qualified motor vehicle is defined as a vehicle used for business with three or more axles, or a vehicle with two axles and a gross vehicle weight or registered gross vehicle weight exceeding 26,000 pounds. Carriers must maintain precise records of all miles traveled and fuel purchased in Connecticut and other member jurisdictions to accurately calculate the tax due or credit owed. DispatchTool assists Connecticut carriers in this process by consolidating GPS-verified mileage data with fuel purchase records, simplifying the preparation of the quarterly CT-IFTA-2 return. The software tracks distance traveled on Connecticut interstates like I-95, I-84, and I-91, ensuring that deadhead miles and off-route excursions are not omitted from the total jurisdictional mileage. By automating the data collection, fleet owners can reduce the risk of manual entry errors that often lead to DRS audits or late-payment penalties. Create a DispatchTool account to start organizing your trip reports and fuel receipts for your next filing deadline.

Registration and Decal Requirements

To register for IFTA in Connecticut, a carrier must have an established place of business in the state where all operational records are maintained. The application is filed via the Department of Revenue Services online portal. Upon approval, the DRS issues an IFTA license and two decals for each qualified motor vehicle. For the 2024-2025 period, the fee for each set of decals is $10.00. These decals must be displayed on both sides of the vehicle's exterior. Failure to display valid decals while operating a qualified motor vehicle on Connecticut roadways can result in a fine of $500 to $1,000 per violation under CT General Statutes § 12-487.

Quarterly Filing Deadlines and Procedures

Connecticut carriers are required to file Form CT-IFTA-2, the International Fuel Tax Agreement Quarterly Tax Return, through the DRS Taxpayer Service Center (TSC). The deadlines are strictly enforced: April 30 for Q1, July 31 for Q2, October 31 for Q3, and January 31 for Q4. If the last day of the month falls on a weekend or legal holiday, the return is due the next business day. Even if no operations were conducted during a quarter, a 'zero' return must be filed to avoid a $50 late filing penalty. The DRS requires electronic filing for all IFTA returns unless a hardship waiver is granted.

Record Keeping and Audit Standards

Under the IFTA agreement, Connecticut carriers must retain records for a period of four years from the filing date. These records must include Individual Vehicle Mileage Records (IVMRs) that detail the date of 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 invoices or credit card receipts showing the number of gallons or liters purchased, fuel type, and the price paid per gallon. The DRS conducts periodic audits to ensure compliance; if records are found to be inadequate, the auditor may impose a 20% assessment based on the best information available.

Interest Rates and Late Payment Penalties

Late payments are subject to a penalty of $50 or 10% of the total tax due, whichever is greater. Interest is calculated on all taxes due to each member jurisdiction at a rate of 1% per month or fraction of a month. For example, a tax liability of $1,000 that is one month late would incur a $100 penalty plus $10 in interest. The interest rate is set by the IFTA Articles of Agreement and is standard across all jurisdictions to ensure consistent enforcement. Payments to the Connecticut DRS must be made in U.S. funds via electronic check, credit card, or ACH transfer.

Connecticut Specific Fuel Tax Rates

As of 2024, the Connecticut diesel fuel tax rate is subject to annual adjustments by the DRS every July 1st. For the period ending June 30, 2025, the state diesel tax is $0.449 per gallon. This is in addition to the federal tax of $0.244 per gallon. Connecticut also utilizes a Petroleum Products Gross Receipts Tax, though this is typically collected at the wholesale level and reflected in the pump price. When filing the CT-IFTA-2, carriers receive a credit for the tax paid at the pump against the tax liability calculated based on their consumption within the state.

The Highway Use Fee (HUF) Distinction

It is critical for carriers to distinguish between IFTA and the Connecticut Highway Use Fee (HUF), which went into effect on January 1, 2023. The HUF applies to any vehicle with a gross weight of 26,001 pounds or more, falling under classes 8 through 13. The fee ranges from $0.025 per mile for vehicles weighing 26,001 pounds to $0.175 per mile for vehicles weighing over 80,000 pounds. While IFTA is reported quarterly, the HUF must be reported monthly on Form HUF-1. Overlapping data points like total Connecticut mileage are used for both, but they require separate filings and payments.

Sources

Connecticut Department of Revenue Services (2024) — https://portal.ct.gov/drs/my-business/ifta/ifta-information IFTA, Inc. (2025) — https://www.iftach.org/ CT General Statutes Chapter 222 (2024) — https://www.cga.ct.gov/current/pub/chap_222.htm

Frequently asked

What vehicles are exempt from IFTA in Connecticut?

Government-owned vehicles, school buses, and certain recreational vehicles used strictly for personal pleasure are exempt. However, any commercial vehicle exceeding 26,000 lbs GVW or having 3+ axles must register if it travels outside Connecticut.

Can I get a temporary IFTA permit in Connecticut?

Yes, for carriers not registered for IFTA, a 72-hour fuel tax permit can be purchased for $21.00. This permit allows travel within Connecticut without a permanent IFTA decal but does not cover other states.

How is the 'Total Fuel Consumed' calculated on the CT-IFTA-2?

You divide the total fleet miles by the fleet's average MPG. For example, if your fleet traveled 100,000 miles at an average of 6.5 MPG, your total fuel consumed for the quarter would be approximately 15,384.6 gallons.

What is the penalty for not filing a Connecticut IFTA return?

Failure to file results in a $50 minimum penalty. Furthermore, your IFTA license may be revoked, which prevents you from legally operating a commercial vehicle in any other IFTA jurisdiction until the delinquency is cleared.

How do I renew my Connecticut IFTA decals?

Renewal applications must be submitted annually through the DRS Taxpayer Service Center by December 31. There is a two-month grace period in January and February, provided the renewal was filed by the deadline.