California Weights and Measures Certification Requirements

California weights and measures certification requirements apply to any device a business uses to determine what to charge a customer by weight, volume, count, or time. Before you can legally use one for a transaction, the device’s make and model must hold type approval, the individual unit must be registered with your county’s sealer of weights and measures, and it must pass inspection and carry a current, visible seal. Re-inspection is periodic, and certain events void the seal before its next scheduled date.

Which Devices Are Covered

California defines “commercial purposes” broadly. Any device that determines the weight, measure, or count of something sold on that basis is covered, along with any device that determines a charge for a service.¹ The statute names taximeters, odometers, timing devices, parcel scales, shipping scales, and scales used to pay agricultural workers as examples.

In practice, that reaches:

Retail scales at checkout counters, delis, produce departments, and farmers’ markets.
Fuel dispensers for gasoline, diesel, compressed natural gas, liquefied petroleum gas, and hydrogen.
EV charging stations that bill by the kilowatt-hour.
Utility submeters for water, electric, and vapor service in apartment complexes, mobilehome parks, and marinas.
Truck scales, livestock scales, and other large-capacity industrial systems.
Parking meters and other devices that charge by elapsed time.

A few uses fall outside the requirement. Scales used purely inside a manufacturing facility, with no customer-facing transaction, do not need commercial certification. Scales used by licensed veterinarians or physicians solely to dose medication are also excluded, as are postal scales weighing packages under 150 pounds, unless the weighing happens in front of the customer.¹

Type Approval Comes Before Anything Else

Before a specific unit can be placed into service, the device’s make and model must hold a Certificate of Approval from the California Type Evaluation Program (CTEP). CTEP evaluates whether the design is accurate, operates correctly, carries the required markings, and resists fraud.² This is a one-time evaluation of the model, separate from the inspection of individual units in the field.

A National Type Evaluation Program (NTEP) certificate may be accepted in place of CTEP, provided the device also meets all applicable California requirements.³ Selling or using a device whose type has never been approved is illegal.⁴ When buying new equipment, get the CTEP or NTEP certificate number from the manufacturer before finalizing the purchase.

Registering with Your County Sealer

Every commercial device in California is inspected and sealed at the county level. The county sealer of weights and measures inspects, tests, and seals each device within the county,⁵ and that office is your point of contact for scheduling inspections, paying registration fees, and resolving problems. Operating in more than one county means dealing with each county separately.

County boards of supervisors set annual registration fees by ordinance under the Business and Professions Code.⁶ Your annual bill has three components:

A business location fee of up to $120 per location.
A CDFA administrative fee, a per-device charge set by the Secretary of Food and Agriculture to fund statewide supervision and the state measurement standards.⁷
A device fee that varies by equipment type and capacity, capped by statute.

Statutory caps on the device fee give a sense of the range:⁶

Computing or electronic counter scales: up to $25 per device.
Mid-range scales (100 to 1,999 lbs): up to $50 per device.
Jewelry and prescription scales: up to $80 per device.
Wholesale and vehicle meters: up to $75 per device.
Heavy-duty scales (2,000 to 9,999 lbs): up to $150 per device.
Heavy-duty scales (10,000 lbs and up): up to $250 per device.
LPG meters: up to $185 per device.
Water submeters in apartments and mobilehome parks: up to $6 per meter.

Counties may collect biennially at up to twice the annual amount. A scale used at a certified farmers’ market does not need separate registration in the county hosting the market as long as it already carries a current seal from another California county.⁶

Preparing the Device for Inspection

Inspectors do not troubleshoot equipment. The device has to be physically accessible, with enough clear space around it for test weights, certified volume containers, or other reference equipment. It also has to be installed to the manufacturer’s specifications. A scale that wobbles on an uneven surface fails before the inspector begins measuring anything.

Have the device calibrated by your own trained staff or a Registered Service Agency before the inspection. Verify that it reads accurately across its capacity range and make any needed adjustments. A device already reading correctly passes quickly. One drifting outside tolerance gets tagged, and you start over, often with a re-test fee.

Inspection, Sealing, and What Happens If It Fails

The county inspector uses certified test standards traceable through the state metrology laboratory to the National Institute of Standards and Technology.⁸ Test methods depend on the device. Retail scales are tested with certified weights at multiple points across their capacity range. Fuel dispensers are tested with certified volume containers at both minimum and maximum flow rates. The pass/fail thresholds trace back to national tolerances established for California by the Secretary of Food and Agriculture.⁹

A device that passes receives an official seal placed for maximum visibility to the customer, showing the date of inspection.¹⁰ A device that fails gets one of two outcomes. If the inspector believes it can be repaired, it receives an “Out of Order” tag and cannot be used commercially until it is fixed and re-inspected. If repair is not feasible, the sealer can condemn, seize, and destroy it.¹¹

Keeping the Seal Valid

A seal is not permanent. Devices need periodic re-inspection on a schedule that varies by device type and by your county’s inspection plan. Beyond scheduled re-inspections, certain events void an existing seal immediately. Repairing, moving, or altering a device in any way that could affect measurement accuracy invalidates the seal. Notify your county sealer and schedule a new inspection before returning the device to commercial use.

Removing or destroying an inspector’s seal or tag is a misdemeanor, unless done by a Registered Service Agency in the course of authorized repair work.¹²

Who Can Legally Repair a Sealed Device

Any company you hire to repair or adjust commercial weighing or measuring equipment has to be a Registered Service Agency (RSA) with CDFA.¹³ The program registers both the agency and the individual employees who perform the work. Using an unregistered technician on a sealed device creates a compliance problem even if the repair itself is competent. Verify registration through CDFA’s Division of Measurement Standards before hiring anyone.

Penalties for Uncertified or Inaccurate Devices

Using an inaccurate or unapproved commercial device is a misdemeanor. The statute lists ten distinct violations, and the ones businesses run into most often include using an incorrect device for commercial purposes, using a condemned device, selling a device without a current seal, and positioning a retail device so the customer cannot read the display.¹⁴ Simply possessing an incorrect device creates a legal presumption that you intended to violate the law.

State penalty guidelines sort violations by code section. Tolerance and specification violations for commercial devices fall into Category C, with penalties of $50 to $250 per violation. Using a device whose type was never approved is a Category B violation, with penalties of $150 to $600.¹⁵ These administrative penalties are separate from the misdemeanor criminal charges, which carry their own fines and possible jail time.

EV Charging Stations Are Not Exempt

Electric vehicle charging stations that bill by the kilowatt-hour are commercial measuring devices under California law and go through the same pipeline as any fuel dispenser. The model must hold CTEP or NTEP type approval, and the station has to be inspected and sealed by the county sealer before commercial use.³

California requires EV chargers to display the electrical energy delivered, the unit price, and the total price for each transaction. Stations using time-based or variable pricing must also show the start and stop time, the energy delivered during each pricing phase, and the total computed price including any additional fees.¹⁶ If you are deploying chargers, confirm CTEP or NTEP status for the specific make and model through CDFA’s certificate database before installation.

1
California Legislative Information. California Code BPC 12500 – Definitions
2
California Department of Food and Agriculture. California Type Evaluation Program (CTEP)
3
California Energy Commission. Requirements for Commercial EV Charging Stations
4
California Legislative Information. California Business and Professions Code 12500.5 – Approval of Types or Designs
5
California Legislative Information. California Code BPC 12210 – County Sealer Inspection Duties
6
California Legislative Information. California Business and Professions Code 12240 – Fees and Charges
7
California Legislative Information. California Code BPC 12241 – Department Administrative Fee
8
California Department of Food and Agriculture. Metrology Program
9
California Legislative Information. California Business and Professions Code 12107 – Tolerances and Specifications
10
California Department of Food and Agriculture. California Business and Professions Code Division 5 – Chapter 5, Section 12505
11
California Legislative Information. California Code BPC 12506 – Condemnation of Incorrect Devices
12
California Department of Food and Agriculture. California Business and Professions Code Division 5 – Chapter 5, Section 12508
13
California Department of Food and Agriculture. Registered Service Agency Program
14
California Legislative Information. California Business and Professions Code BPC 12510 – Misdemeanors
15
Legal Information Institute. California Code of Regulations Title 4 Section 4802 – Penalty Guidelines
16
California Department of Food and Agriculture. California EVSE Regulation Reference Document