Who needs a trucking permit in Washington?

Dec. 13, 2025, 6:07 p.m.
In Washington, trucking permits are required before operating on public highways when your vehicles or loads exceed the state’s legal size or weight limits. These permits are issued through the Washington State Department of Transportation (WSDOT) or, for some local streets, city agencies.
Trucking Permits in Washington

1. Vehicles or Loads That Exceed Legal Dimensions

You need a permit if your vehicle or its load exceeds any of the standard legal limits, such as:

  • Width greater than 8 feet 6 inches

  • Height greater than 14 feet

  • Length greater than standard legal limits (e.g., over 53 feet for trailers or combinations greater than 75 feet)
    These oversized conditions trigger the requirement for a permit for that trip or operation. 

2. Vehicles or Loads That Exceed Legal Weight Limits

A permit is required if your vehicle’s weight goes beyond the legal axle or gross weight limits established by state law.

  • For example, gross weights or axle weights that exceed what’s allowed without special permits must be permitted. 

3. “Non-divisible” Loads

Permits are generally required only for non-divisible loads — loads that cannot reasonably be reduced, dismantled, or separated into smaller units. If the load can be divided to fit within legal limits, a permit normally will not be granted. 

4. Interstate Carriers Entering Washington

If you operate overweight/oversize commercial vehicles registered outside Washington and cross into or through the state, you must obtain the appropriate state permit before entering (unless exempt). This also applies to vehicles that don’t pay Washington fuel tax under IFTA and need a trip or fuel permit to operate legally while passing through the state.  

5. Local City Permits

In addition to state permits, some cities (like Seattle) require local over-legal truck permits for oversized or overweight vehicles operating on city streets. These are in addition to WSDOT permits if your route takes you onto local roads.

Key Takeaways

You must obtain a Washington trucking permit if you are:
 Operating a commercial vehicle or combination whose dimensions exceed state legal limits. 
 Hauling weight above Washington’s legal weight limits. 
 Moving a non-divisible oversize/overweight load on Washington highways. 
 Entering or crossing Washington with permitted oversize/overweight vehicles from other states without state fuel tax.  
 Operating within certain cities that have additional permit requirements.

 

https://wsdot.wa.gov/engineering-standards/all-manuals-and-standards/manuals/permit-desk-guide