IFTA Tax Rates in Connecticut (2026)

Key numbers at a glance

Connecticut is a small state with an outsized IFTA footprint — every truck running I-95 between New York and Boston or I-84 toward Hartford burns miles here, and the diesel rate is among the highest in the Northeast. The rate resets every July 1 by formula, so Q2 and Q3 returns use different numbers more years than not. The figures below come from the official IFTA Inc. fourth quarter 2026 tax rate matrix and Connecticut DRS Announcement 2026(2) — as of Q4 2026 — always confirm the current quarter's official IFTA matrix before filing (this quarter's matrix is not final until December 4, 2026). Every jurisdiction compared is on the IFTA rates by state hub.

IFTA tax rates in Connecticut

Connecticut's IFTA diesel rate combines two levies, and the state announces the fresh figure each summer — DRS Announcement 2026(2) set the diesel rate for July 1, 2026 through June 30, 2027:

The formula ties the diesel rate to wholesale diesel prices, which is why it drifts almost every July — 48.9 cents became 49.9 cents on July 1, 2026, the kind of one-cent move that quietly breaks a spreadsheet built on last year's rates. There is no separate Connecticut surcharge schedule: unlike Indiana's dedicated surcharge line or Virginia's two-line base-plus-additional reporting, the gross earnings tax is already folded into the single 49.9-cent figure you file.

How Connecticut IFTA affects your filings

Your Connecticut line each quarter is Connecticut miles divided by fleet MPG, times $0.499 for diesel. Take a Hartford to New York City to Boston run at 6.5 MPG:

Connecticut is only 30% of the miles but 40% of the tax — the per-mile cost of Connecticut diesel tax here is roughly 7.7 cents versus 3.7 cents in Massachusetts. Flip the fueling: buy all 61.5 gallons in Connecticut and you prepaid $30.71 against $22.78 owed, stranding about $7.93 until refund time. Buy them in Massachusetts and you prepaid $14.77 against $22.78, leaving $8.01 due. For a state you cross in an hour or two, the fueling decision is worth more than the miles suggest. Run your own lane mix in the IFTA calculator, and file Q4 with Q4 rates — a July 1 formula state punishes stale spreadsheets twice a year.

Connecticut-based carriers file with DRS as the base state; everyone else reports Connecticut as a line item. Either way the deadlines are uniform — April 30, July 31, October 31, January 31 — with late penalties typically $50 to $100 plus interest per quarter.

Fueling strategy around Connecticut: price minus tax

Shop by net price: pump price minus the state tax, then check the rates ahead. The Q4 2026 regional map — Massachusetts 24.0 cents, New York 38.0, Rhode Island 40.0, New Jersey 56.1 — makes Connecticut a pass-through fueling state: cheaper than New Jersey, dearer than nearly everything north or west. On lanes that touch Massachusetts (I-84 through Sturbridge or I-90 pickups), fill there — 25.9 cents a gallon less than Connecticut, roughly $26 per hundred gallons. Heading into Rhode Island or points east, Rhode Island's 40.0 cents is the better fill than Connecticut by about a dime. Only when crossing the Hudson into New Jersey does buying Connecticut diesel first make sense, since New Jersey's 56.1 cents is the region's highest. A hundred gallons a week moved from Connecticut to Massachusetts pumps is over $1,300 a year in tax timing — one of the sharpest edges on the Eastern Seaboard. Weekly price swings can erase it, so tie the call to your freight with the fuel surcharge guide and let the surcharge fund the pump while the fueling plan keeps the IFTA line flat.