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Dyed diesel

Things to know

TAP is now available for Dyed Diesel customers. We may experience some delays with the implementation of the new system. Please be patient with our staff.

Dyed diesel is fuel with red dye added to show there are no federal or state fuel taxes paid. Other industry names for dyed diesel are marked fuel, farm fuel, "red dyed" diesel.

Common uses

Common uses of dyed diesel are non-highway farming equipment, construction equipment, generators, and marine vessels.

Using dyed diesel

Dyed diesel users must have a license for on-road use. You can now register for a dyed diesel user license and manage your account using TAP – PRFT Taxpayer Access Point. This license allows approved government agencies and organizations to use dyed special fuel (diesel or biodiesel) when operating licensed motor vehicles on public roadways. The Internal Revenue Services (IRS) approved users are:

  • Public school districts
  • Nonprofit educational organizations
  • Government agencies

Legal non-highway use

  • Tractors and farm equipment ("Q" decal vehicles) used within 25 miles of the registered address
  • Construction equipment
  • Stationary engines, such as a generator or welders
  • Marine vessels

Illegal use

It's illegal to use dyed diesel in vehicles that drive on Washington State public roadways or highways. Examples of illegal use include:

  • Operating a farm vehicle, registered with a "Q" decal, with dyed diesel beyond the 25-mile radius.
  • Having dyed diesel in the fuel tank of a licensed vehicle.
  • Fueling a licensed vehicle with dyed diesel from your bulk storage tank (both the vehicle and the tank are subject to penalties).
  • Using a farm vehicle that's registered in Canada and filled with 'marked fuel" on United States highways.

Penalties for illegal use of dyed diesel

Each violation will result in a fine of $10/gallon or $1,000 per tank, whichever is greater.


  • If you have 3 registered vehicles, each with a 20-gallon capacity, you could face a fine of $3,000. (3 vehicles x $1,000 minimum fine = $3,000)
  • If you fuel a licensed vehicle from your own 150-gallon dyed diesel slip tank or bulk storage tank, you could face a fine for both the tank and the vehicle:
    • $1,500 for the bulk storage tank ($10 x 150 gallons = $1,500), and:
    • $1,000 for the vehicle tank ($1,000 minimum fine)

Investigation and enforcement

Fuel Tax Evasion Unit

The Fuel Tax Evasion Unit is a partnership between us and the Washington State Patrol (WSP). The unit:

  • Investigates fuel tax evasion
  • Captures data
  • Takes phone calls from the tip line, 800-497-FUEL (800.497.3835)

Washington State Patrol enforcement

WSP conducts thousands of "dips" to check fuel tanks for dyed fuel and determine if the operator is using the fuel against the law. Violators will receive a fine, which may appear on their record as a felony or misdemeanor.

How to report suspected fuel tax evasion

You can report fuel tax evasion by:

  • Phone: 800-497-FUEL (800.497.3835)
  • Email: evasion@dol.wa.gov
  • Mail to:
    Fuel Tax Investigations Unit
    Department of Licensing
    PO Box 9228
    Olympia, WA 98507-9228

You may remain anonymous. If you leave your name and phone number, a task force member will call you back. We investigate all information and keep it confidential.

Refund for tax-paid non-dyed (clear) diesel

You might be eligible for a refund of the Washington State fuel tax:

  • If you're an individual or company who bought at least 41 gallons of Washington tax-paid fuel in the past 13 months, visit the Fuel Tax Refund page for more information about qualifications and filing for a refund.

More information about dyed diesel

Related laws and rules

Related information

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