Connecticut IFTA Filing — Rates, Portal & Deadlines
Everything an owner-operator needs to file IFTA in Connecticut — current quarterly rates, the base-state portal, surcharge handling, and the common mistakes that lead to penalties.
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Connecticut IFTA at a glance
| IFTA jurisdiction | Yes |
|---|---|
| Administering agency | Connecticut Department of Revenue Services |
| Filing portal | Open Connecticut portal |
| Filing frequency | Quarterly (Apr 30, Jul 31, Oct 31, Jan 31) |
| Surcharge | No |
| E-file required | No (electronic preferred, paper accepted) |
| Late penalty | $50 or 10% of tax due, whichever is greater |
| Record retention | 4 years (fuel receipts, mileage records, ELD logs) |
What's specific to Connecticut
Connecticut requires both IFTA filing (quarterly) and the Highway Use Fee (monthly, since 2023) for qualifying heavy trucks. Missing the HUF is one of the most common compliance gaps for carriers running the I-95 corridor.
Other filings besides IFTA in Connecticut
Heavy trucks operating in Connecticut are responsible for additional state-level filings on top of (or instead of) IFTA. Missing these is one of the most common compliance gaps for owner-operators.
Connecticut Highway Use Fee (HUF)
Connecticut implemented a separate Highway Use Fee on Class 8+ heavy trucks in January 2023 — a per-mile fee that varies by GVW and is filed monthly through the DRS, separate from IFTA.
Open the official program pageHow to file IFTA in Connecticut
- Compile your quarterly mileage by jurisdiction — including deadhead and detour miles. ELD reports (Samsara, KeepTruckin / Motive, Geotab) export this directly.
- Compile your fuel purchases by jurisdiction. Fleet-card CSVs from EFS, Comdata, WEX, or RTS produce this in one click; if you're paying by personal card, you'll be reconciling receipts manually.
- Calculate fleet MPG (total miles ÷ total gallons), then taxable gallons per state (state miles ÷ fleet MPG). Use the free IFTA calculator if you'd rather not do this by hand.
- Apply the current quarterly rate for Connecticut, then net it against fuel tax already paid at the pump in Connecticut.
- File through the Connecticut Department of Revenue Services IFTA portal by the quarterly deadline.
- Retain receipts, mileage records, and ELD reports for at least 4 years in case of audit.
Common Connecticut IFTA mistakes
Skipping Connecticut Highway Use Fee (HUF)
Connecticut Highway Use Fee (HUF) is filed separately from IFTA. Carriers based outside Connecticut who only transit through often miss it entirely — and discover the gap at the next compliance review.
Filing a zero return late
Even if you didn't run Connecticut this quarter — or didn't run at all — you're still required to file. A late zero return triggers the same $50 minimum penalty as any other late filing.
Mixing up where you fueled vs. where you drove
Fuel purchased at the Connecticut state line counts for the state at the pump, not the state you drove next. This is where shoebox-of-receipts owner-operators most often lose IFTA credits.
Using rate-con planned miles instead of actual driven miles
The rate con says one number. Your actual mileage — including detours, fuel stops off-route, and rerouting around weather — is usually 5-10% higher. IFTA wants what you actually drove.
Run your Connecticut IFTA in 3 minutes — free
Upload your rate cons and fuel receipts. We pull the Connecticutmiles and gallons, apply current quarterly rates, and hand you a filing-ready PDF.
Open the free IFTA calculatorNo signup required. One full calc per IP.
Other state IFTA guides
IFTA Filing Guide for Owner-Operators
Step-by-step IFTA primer covering all 48 states.
How IFTA Math Works
Worked examples of taxable gallons, credits, and net tax.
Owner-Operator Tax Deductions
Schedule C deductions every owner-operator can claim.
Trucking Compliance Checklist
Every DOT, FMCSA, and state filing in one place.