Get your scale legal for trade, step by step.

Five steps for a scale owner in the United States, in the order they happen. Pick your state once; the steps show your office and your state’s rules. Every rule here names its source.

Your state

Step 1 of 5

Is your scale NTEP certified?

A scale used to buy or sell by weight needs a model that passed type evaluation: an NTEP Certificate of Conformance, issued through NCWM. The certificate number sits on the scale’s data plate; an inspector looks for it first. For internal use only (inventory, checks), a non-NTEP scale is fine.

Source: NIST Handbook 44 (2026), Section 1.10 General Code, G-S.1 Identification (the markings a device must carry, including the Certificate of Conformance number), read the current edition on nist.gov. The states require the certificate through their adoption of NIST Handbook 130 (Uniform Regulation for NTEP), NIST Office of Weights and Measures.

Verify a certificate NCWM NTEP database

Step 2 of 5

Your state weights and measures office, and what it requires.

Each state runs its own program, usually inside the Department of Agriculture. Some require you to register the device or get a permit before use, with a fee; some delegate inspections to a county or city office. Pick your state above to see yours.

Source: each state’s own page on this site cites the statute, the agency and the form; verified against the NIST OWM state directory on Oct 19, 2026. Where a state differs from the general rule, the state page says so.

Find your office

Step 3 of 5

Have it installed and calibrated by a registered service company.

Most states license or register the companies that install, repair and place commercial scales into service, and many require a placed-in-service report to the office. A registered company sets the scale level and plumb, calibrates it with certified test weights, and files the report where one is required. Work by an unregistered installer may not count.

Source: NIST Handbook 44 (2026), Section 1.10 General Code, G-UR.2 Installation Requirements and G-UR.4 Maintenance Requirements; G-T.1 sets the tighter acceptance tolerances for a device first tested within 30 days of being placed in service, nist.gov. Your state’s licensing rule is on its state page.

Find a registered scale company Send one service request

Step 4 of 5

The inspection and the seal.

The weights and measures official tests the scale with certified weights and, if it passes, seals or tags it for commercial use. What the inspector checks, by the book:

The identification plate and the NTEP certificate number (Handbook 44, Section 1.10, G-S.1).
Installation and use: level, foundation, the right scale for the job, how it is loaded and read (G-UR.1 Selection, G-UR.2 Installation, G-UR.3 Use).
Accuracy against tolerance with certified test weights, by accuracy class and division size (Section 2.20 Scales, Tolerances T, and Notes N for the test procedure).
Maintenance and seals on the adjustment points (G-UR.4 Maintenance).
A failing scale is rejected and tagged until it is repaired (Handbook 44, Appendix A, 6.1 and 7.1).

Source: NIST Handbook 44 (2026), Sections 1.10 General Code and 2.20 Scales, Appendix A Fundamental Considerations, read the current edition on nist.gov. Each state adopts Handbook 44 with its own changes; the inspection cycle (often annual) and fees are set by your state or county, confirm them with the office in step 2.

Compliance FAQ Handbook 44 (PDF)

Step 5 of 5

Keep the record.

Register the scale with ScaleRegistry: it gets a permanent Registry ID and a QR label, every calibration and repair goes on its record, the next calibration date is on file before anyone asks, and the public record opens from the label for an inspector, a buyer or an auditor, no login. Service companies keep their customers’ scales here too.

ScaleRegistry is a registry, not a regulator. Confirm current requirements with the weights and measures office responsible for your location.