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Washington Scale Certification & Weights and Measures

✓ Sources checked July 11, 2026; office details updated September 22, 2026
Start here: WSDA handles commercial scales in most of Washington. Inside Seattle, the city runs its own program (SMC ch. 7.04) and inspects commercially used scales: Seattle Weights & Measures, (206) 386-1267. Call (360) 902-2035

Washington runs a state-managed weights and measures program — outside Seattle (and any other city that runs its own sealer program), commercial scale owners deal with the state agency directly. If you operate a commercial scale in Washington — at a warehouse, farm, recycling yard, retail store, or truck stop — here is who regulates it, what the law requires, and exactly who to contact.

Who inspects commercial scales in Washington?

State-run: WSDA Weights and Measures inspects and tests commercial devices statewide and conducts unannounced inspections; owners contact the WSDA W&M Program in Olympia. RCW 19.94.015/.280 lets a city that operates its own city sealer program register and inspect devices inside that city; everywhere else the state program applies. The City of Seattle runs its own program (SMC ch. 7.04): the city inspects commercially used scales inside Seattle (Seattle Consumer Protection, (206) 386-1267).

What Washington requires of scale owners

Every commercial weighing/measuring device must be registered annually; registration is handled as an endorsement on the Washington business license through the Department of Revenue's Business Licensing Service and the fee is paid with the business license application or renewal (RCW 19.94.015). Devices must carry an NTEP Certificate of Conformance, and rejected/repaired devices must be serviced by a service agent registered with WSDA.

Devices used to buy or sell by weight must comply with NIST Handbook 44 — in practice this means an NTEP-certified, legal-for-trade scale. Confirm requirements for your device class with the office listed here.

Getting a scale into service — 4 steps

  1. Buy a legal-for-trade (NTEP-certified) scale appropriate for your application and capacity.
  2. Confirm registration and licensing requirements with the Washington State Department of Agriculture at 360-902-2035 — or, inside Seattle, Seattle Consumer Protection at (206) 386-1267 — before the scale enters commercial use.
  3. Arrange compliant installation and calibration. Where required, placing-in-service must be done by a licensed or registered service company.
  4. Stay compliant. Pass required inspections, keep calibration current, retain service records.

Common questions

What is NTEP certification?
NTEP (the National Type Evaluation Program, administered by the National Council on Weights and Measures) evaluates a scale model's design against NIST Handbook 44 requirements and issues a Certificate of Conformance. Nearly every state requires an NTEP-certified device for commercial (legal-for-trade) weighing; confirm the rules for your device with the office listed on this page.
Where do I find official forms and fees?
Use the licensing and forms links in the office panel, or contact the office directly — fee schedules change and some are published only in application documents.

Need calibration, repair, or installation in Washington?

Browse companies listed as serving Washington in the ScaleRegistry directory and contact them directly, and check the official licensing and registration information for Washington. Listings are not ranked or endorsed, and ScaleRegistry does not route requests to any company.

Find companies in Washington
Sources: cms.agr.wa.gov/WSDAKentico/Documents/Pubs/AGR7-2503-… | app.leg.wa.gov/RCW/default.aspx?cite=19.94.015 | cms.agr.wa.gov/WSDAKentico/Imported/404E-Recreationa… | agr.wa.gov/services/inspections-and-investigations/i… | www.seattle.gov/business-regulations/weights-and-mea…