Compliance FAQ
40 plain-English answers — NTEP, calibration, state rules, Handbook 44, and buying right. Updated October 9, 2026.
NTEP & Certification
What is NTEP certification?
NTEP (National Type Evaluation Program) is run by the National Council on Weights and Measures (NCWM). It evaluates a scale model's design against NIST Handbook 44 requirements and issues a Certificate of Conformance (CC). Nearly every state requires an NTEP-certified device for commercial (legal-for-trade) weighing.
What does "legal for trade" mean?
A legal-for-trade scale is approved for buying or selling by weight. In practice that means the model is NTEP-certified (has a Certificate of Conformance) and the individual device passes your state or county Weights & Measures inspection and is sealed for commercial use.
Do I need an NTEP scale?
If you buy, sell, or charge based on weight — recycling, freight, food sold by weight, laundry, cannabis, farm sales — you need a legal-for-trade (NTEP) scale in nearly all states. For internal use only (inventory counts, quality checks, estimating) a non-NTEP scale is fine and costs less.
How do I check if a scale is NTEP certified?
Look for the CC (Certificate of Conformance) number on the device's data plate, then verify it in the NCWM's free NTEP database.
What is a Certificate of Conformance (CC) number?
The CC number is issued by NCWM when a device type passes NTEP evaluation. It appears on the scale's data plate and is your proof the model is approved for commercial use. Inspectors check it during certification, and you can verify any CC number in the public NTEP database.
Is NTEP certification the same as calibration?
No — three different things. NTEP is type approval of the model's design. Calibration is adjusting and verifying your individual unit's accuracy. Certification (sealing) is your state or county inspector approving your specific device for trade use. A commercial scale typically needs all three.
What are scale accuracy classes (Class III, III L)?
Handbook 44 groups devices into accuracy classes. Most commercial bench and floor scales are Class III; vehicle and livestock scales are typically Class III L. The class and the number of divisions (e.g., 5,000 d) define the certified resolution and the tolerances inspectors apply.
Does NTEP certification expire?
A Certificate of Conformance stays valid for the device model — you don't renew NTEP itself. What recurs is your device's state or county inspection (commonly annual) and any registration or permit your state requires.
State Requirements
Who regulates commercial scales in the U.S.?
Each state runs its own Weights & Measures program, usually inside the Department of Agriculture. Some states (like California, New York, and Ohio) delegate inspections to county sealers or auditors. NIST publishes the technical standards (Handbook 44) that states adopt, but NIST itself does not inspect scales.
Do scale laws differ from state to state?
Yes. States differ on device registration or permits, who may install and repair commercial scales, inspection frequency, and fees. The biggest split, per our directory: 39 states plus DC inspect with state field staff, 7 states use a mix of state and local officials, and 4 (California, New York, Ohio, and Rhode Island) rely mainly on county or municipal officials. Our directory has a sourced page for every state and DC.
Do I need to register my scale with the state?
Depends on the state. Texas requires annual device registration, Florida requires a device permit before commercial use, Ohio requires permits for vehicle and livestock scales, while some states have no owner registration at all. Check your state's page for the exact rule and forms.
Who can install or repair a commercial scale?
Many states license or register the service companies and technicians that install, repair, or place commercial devices into service — for example, California's Registered Service Agencies. The rules differ by state: in Florida, a new commercial scale must be inspected and approved by a state inspector, or tested and placed in service by a registered scale service agency, before it is used. If your state requires a registered or licensed installer, work by an unregistered one may not meet that requirement — check your state page or ask your weights and measures office.
What happens during a Weights & Measures inspection?
The inspector tests your device with certified test weights against Handbook 44 tolerances, checks the NTEP data plate and seals, and verifies proper installation and use. Passing devices are sealed or tagged for commercial use; failing devices are tagged out of service until repaired.
What if my scale fails inspection?
The weights and measures official can reject the device and order it corrected, and usually tags or marks it as rejected (NIST Handbook 44, 2026 edition, Appendix A, sections 6.1 and 7.1). Follow the official's instructions on whether it may be used while it is repaired. Who may return it to trade use, and whether the repair must be reported, depends on your state or county: in some states a licensed or registered service company repairs it and reports the repair, and the official may retest it. Keep your repair records.
How often are commercial scales inspected?
Annual inspection is the most common cycle, but it varies by state, county, and device type — some jurisdictions inspect more or less frequently based on risk and complaint history. Your state page lists the program contact who can confirm your cycle.
What is a county sealer?
In county-based states (California, New York, Ohio, and others), the county sealer — sometimes the county auditor — is the local official who inspects and seals commercial weighing devices. If you're in one of these states, your county office is your first contact, not the state.
Can I buy a scale from out of state?
Yes — compliance is based on where the scale is used, not where you buy it. Buy an NTEP-certified model from anywhere (many suppliers ship nationwide), then follow your state's placing-in-service and inspection rules. Our state pages tell you exactly what applies.
What is a placed-in-service report?
A report a registered or licensed service company sends to the weights and measures office after it installs or repairs a commercial device and puts it into use. Who receives it, and when, depends on the jurisdiction: in California the service agency must notify the county sealer of any repair in writing within 24 hours (CDFA Registered Service Agency guide), and states such as Florida and Utah publish a Placed-in-Service Report form. The report does not replace official inspection — the official may still test the device (NIST Handbook 44, 2026 edition, General Code G-T.1, sets the tolerances for a device first tested within 30 days of being placed in service). Check your state page or weights and measures office for the form and where it goes.
What is a public weighmaster?
A licensed person who issues official certificates of weight — common at truck scales, recyclers, and grain operations. Most states license weighmasters separately from device requirements (e.g., New York and Pennsylvania both license weighmasters). If you issue weight tickets to third parties, you likely need one.
Calibration & Service
How often should I calibrate my scale?
For legal-for-trade scales, at minimum keep your state's inspection cycle. For accuracy-critical operations, best practice is quarterly to annual calibration, plus a check after any move, impact, or suspicious readings. High-throughput or harsh environments need the shorter end of that range.
What's the difference between calibration and certification?
Calibration adjusts and verifies your scale against reference standards. Certification is the government act of inspecting and sealing the device for commercial use. A calibrated scale isn't automatically certified — and in most states, adjustments to a trade device must be made by a licensed service company so it stays certified.
Who is allowed to calibrate my scale?
Non-commercial scales: anyone (follow the manual and use accurate test weights). Commercial scales: adjustment and return-to-service generally must be done by your state's licensed/registered service company or technician, or the device loses its sealed status. Every state page links the official registry of licensed companies.
What are certified test weights?
Weights calibrated against NIST-traceable standards, used to test and calibrate scales. Service companies are required to have their test standards re-certified periodically (every 1–2 years in most states). If you self-check a non-trade scale, using traceable weights makes the check meaningful.
Can I calibrate my own scale?
For internal-use scales, yes — most indicators have a built-in calibration mode described in the manufacturer's manual. For legal-for-trade devices, self-adjustment usually breaks the seal and the law: use a licensed service company so the device keeps its certified status.
Why is my scale drifting or reading wrong?
Common causes: the scale isn't level, debris under the platform, temperature swings, shock/overload damage to a load cell, moisture in junction boxes, or a failing indicator. Re-zero, re-level, and clean first; if drift continues, a load cell test is the next step, which a qualified service technician can perform.
What does "NIST traceable" mean?
It means an unbroken, documented chain of calibrations connects a measurement back to national standards maintained by NIST. When you buy calibration service or test weights, ask for a traceable certificate — auditors and inspectors do.
How much does scale calibration cost?
It varies with device type, capacity, and location — bench scales cost far less than truck scales (which need a test truck and certified weights). Costs are best confirmed by requesting quotes from licensed service companies in your area.
Standards & Regulation
What is NIST Handbook 44?
The rulebook for commercial weighing and measuring devices in the U.S. — specifications, tolerances, and technical requirements, updated annually by NIST's Office of Weights and Measures and adopted by the states. The current edition (2026) is free to read on NIST's site.
Where can I read Handbook 44 for free?
NIST publishes every edition free. The current-edition page always links the latest PDF — no purchase needed. Our resources page also links the NTEP database and NCWM so you have the full standards toolkit in one place.
What is the NCWM?
The National Council on Weights and Measures — the standards organization where state officials, industry, and federal advisors set U.S. weights and measures policy. NCWM runs the NTEP program and votes the annual updates that become each new edition of Handbook 44.
What does NIST's Office of Weights and Measures do?
NIST OWM publishes the handbooks (44, 130, 133), trains state inspectors and metrologists, and supports state standards labs. It sets the technical foundation but doesn't inspect devices — that's your state or county program.
Does NTEP certification work in Canada?
No — Canada has its own approval system through Measurement Canada. A U.S. NTEP certificate alone doesn't make a device legal for trade in Canada (some models hold both approvals). If you operate on both sides of the border, check each device's approvals before buying.
What are Handbook 44 tolerances?
The allowable error limits inspectors apply when testing a device — tighter "acceptance" tolerances for new or just-repaired devices, and "maintenance" tolerances for devices in service. They scale with the device's accuracy class and division size.
Buying Guidance
Floor scale or bench scale — which do I need?
Bench scales (up to ~100–500 lb) suit parcels, parts, and food prep. Floor scales (1,000–20,000 lb, 2'x2' up to 10'x10') handle pallets, drums, and gaylords — choose by your heaviest regular load and how you'll load it (pallet jack, forklift, or by hand).
What capacity scale should I buy?
Take your heaviest expected load, add the container/pallet weight, then add 25–50% headroom for safety and longevity. Don't overshoot wildly — bigger capacity means larger divisions (coarser readability). If you need fine resolution and high capacity, look for dual-range models.
Why do NTEP scales cost more than non-NTEP?
NTEP models carry a design that has been type-evaluated against NIST Handbook 44 and issued a Certificate of Conformance through the National Type Evaluation Program, which adds engineering and program costs. NTEP is administered by the NCWM — an association of weights and measures officials and industry, not a government agency — but state jurisdictions are what require the certificate. If you sell by weight it's the price of doing business legally; if you never sell by weight, save the money and buy non-NTEP.
What is a scale indicator and does it need to match?
The indicator is the display/control head wired to your platform's load cells. For trade use, each element must have an NTEP Certificate of Conformance (CC), and the combination must meet Handbook 44 compatibility requirements. Confirm with your installer or Weights & Measures office.
What should I know about load cells?
Load cells are the sensors that do the weighing — floor scales typically use four shear-beam cells. For trade use, cells must be NTEP-rated; for washdown or corrosive environments choose stainless steel with proper IP ratings. Cells are replaceable — a damaged cell doesn't mean a dead scale.
What should I know before buying a truck scale?
Decide NTEP vs non-NTEP first: billing by weight requires NTEP and full state compliance (some states also require installation permits and weighmaster licensing to issue tickets). Axle scales and weigh pads are economical for check-weighing and overload prevention but most aren't legal for trade. Foundation and site prep drive total cost.
What do food and washdown environments need?
Stainless-steel construction and sealed, IP-rated load cells and indicators built for washdown chemicals and moisture. If you also sell by weight (e.g., meat, seafood), the system must be NTEP-certified on top of being washdown-rated.
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