If you’re an owner-operator or small fleet running freight in and out of Seattle, you deal with chain requirements on the mountain passes, a hazmat ban in the SR 99 tunnel, tunnel tolls by axle, ferry fares by length, and a Washington tax on in-state hauling that most carriers from outside the state have never heard of. If your books don’t separate those costs, your cost per mile is a blend of everything and a true measure of nothing, and every rate you accept is measured against the wrong number.
Chains Are Required Equipment, Not an Option
From November 1 to April 1, every vehicle over 10,000 pounds gross vehicle weight must carry at least two extra tire chains on Washington’s listed mountain routes, whatever the weather. The list includes I-90 from North Bend to Ellensburg over Snoqualmie Pass, I-82 from Ellensburg to Selah, US 2 from Dryden to Index, US 12 from Packwood to Naches and SR 410 from Enumclaw to Naches. The rest of the year, chains are required when posted.
Chains, chain-up time and slow winter passes are the cost of running the mountain lanes. Put them on the Seattle-to-eastern-Washington lane where they belong, and you’ll see what those winter loads really pay.
The SR 99 Tunnel: No Hazmat, Tolls by Axle
Hazardous materials are prohibited in the SR 99 tunnel under downtown Seattle, because of its fire suppression system and the City of Seattle fire code. The same federal route list notes that flammable loads can’t use the I-5 tunnel under the convention center, or the I-90 tunnels at Mercer Island and the west side of Lake Washington, while their sprinkler systems are down or being tested. A hazmat load through Seattle has to plan around all of it.
For everyone else, the tunnel is tolled by axle count and time of day. On a weekday afternoon a five-axle truck pays $7.00 with a Good To Go! pass and $12.00 by mail. That gap is pure overhead if your truck isn’t on a pass, and the tolls belong to the loads that used the tunnel.
Ferries Charge by Length
Washington State Ferries charge vehicles 22 feet and longer by length and height, and a peak-season surcharge applies to full-fare vehicles from May 1 through September 30. Commercial vehicles pay at the tollbooth; tickets can’t be bought online.
If you deliver to the islands or the Kitsap Peninsula, the ferry fare is part of that customer’s cost. Left in general expenses, it makes island work look more profitable than it is.
Washington Taxes Hauling Inside the State
Washington has no income tax, but it does tax trucking revenue. Hauling for hire that both starts and ends in Washington falls under the state’s public utility tax at 1.926% of gross, in place of the business and occupation tax. Hauls with one end outside Washington qualify for a deduction, and hauls entirely within a city, or within five miles of it, fall under a lower urban transportation rate of 0.642%.
That makes it a bookkeeping problem as much as a tax one. To file correctly, every load has to be coded as in-state, interstate or urban, and the revenue split to match. A carrier who lumps it all together either overpays or gets it wrong on an audit.
IFTA When Washington Is Your Base State
Washington-based carriers file IFTA through the Department of Licensing. Returns are due quarterly, by the last day of the month after each quarter ends (April 30, July 31, October 31 and January 31), and you file even if your trucks never left Washington that quarter.
Washington’s diesel tax is 59.5 cents a gallon on the IFTA rate table for the third quarter of 2026, among the higher rates in the country. Where you buy fuel and where you run your miles both change what you owe, so clean records by state matter every quarter.
Tolls, tax rates and requirements on this page are as of November 2026 and can change.
Remote Bookkeeping That Knows Seattle Lanes
COGS Bookkeeping is a remote bookkeeping service for owner-operators and small trucking fleets. What we bring is an understanding of how Seattle and Washington routes change your numbers, and books set up to show it.
Revenue coded for Washington’s tax. In-state, interstate and urban hauls separated, so the public utility tax comes out right.
Route costs where they belong. Tunnel tolls, ferry fares, chains and winter delays tied to the lane or customer that caused them.
IFTA filed every quarter. Miles and fuel tracked by jurisdiction all quarter, so the return isn’t a scramble.
A P&L that shows which customers pay. Not just what they paid you, but what their loads cost you to run.
Know Your Seattle Cost Per Mile
If you run freight through Seattle and you’re not sure what your true cost per mile is, start with our free Cost-Per-Mile Calculator. It takes about ten minutes, needs no email, and gives you your number.
Want help reading it? Talk to us and we’ll walk through what it means for the loads you take.
Common Questions
Do I need a bookkeeper in Seattle?
No. COGS Bookkeeping works remotely with owner-operators and small fleets. You send settlements, fuel receipts and statements electronically, and you get your books, reports and IFTA filing back the same way.
Can trucks carrying hazardous materials use the SR 99 tunnel in Seattle?
No. Hazardous materials are prohibited in the SR 99 tunnel because of its fire suppression system and the City of Seattle fire code, according to the federal hazmat route registry.
What tax does Washington charge on trucking revenue?
Hauling for hire that starts and ends in Washington is subject to the public utility tax at 1.926% of gross, in place of the B&O tax. Interstate hauls qualify for a deduction, and hauls within a city or five miles of it use the urban transportation rate of 0.642%.