Weights and Measures Compliance for EV Charging in California
A complete guide for station owners and operators
California is leading the way in electric vehicle adoption, and with that growth comes a greater need for reliable, accurate, and transparent EV charging infrastructure. If you own and operate charging stations in the state, you’re not just providing a service, you’re running a regulated commercial measuring device. That means the same rules that apply to gas pumps and grocery store scales also apply to your chargers.
One of the most important parts of that regulatory framework is the California Type Evaluation Program (CTEP). If you’re a station owner in California, CTEP compliance isn’t optional. It’s required by law before your charging stations can be used to bill customers for energy. In this article, we’ll walk you through exactly what CTEP is, what your responsibilities are as a station owner, the steps involved in compliance, and how EV Range helps you navigate the process from start to finish.
What is the California Type Evaluation Program (CTEP)?
The California Type Evaluation Program is the state’s formal certification process for any commercial measuring device used to determine the amount of a commodity being sold. In the EV charging world, that commodity is electricity, measured in kilowatt-hours (kWh).
CTEP is administered by the Division of Measurement Standards (DMS), part of the California Department of Food and Agriculture (CDFA). While CDFA might not be the first agency that comes to mind for EV infrastructure, its Measurement Standards division has long been responsible for ensuring commercial devices are accurate, reliable, and resistant to fraud.
If you’ve ever noticed a small seal on a gas pump or a grocery store scale, you’ve seen the end result of a similar process. That seal tells customers the device has been inspected, tested, and certified for accuracy by an approved authority. CTEP does the same for EV charging stations.
Why EV Chargers Are Considered Commercial Measuring Devices
EV charging stations that bill customers for the amount of electricity delivered are more than just plugs connected to power. They are measuring instruments that directly determine how much a customer is charged.
Because customers are paying based on the kWh displayed on the charger, the state treats each unit as a commercial measuring device. That means the station must pass strict testing to confirm it measures accurately, displays the correct information, meets all labeling requirements, and includes safeguards to prevent fraud or tampering.
If a station doesn’t meet these standards, it cannot legally be used for billing in California.
How the CTEP Evaluation Works
The CTEP process is designed to verify that a new charger model meets all legal requirements before it can be sold, installed, and used for commercial purposes in the state.
Here’s what happens during a CTEP evaluation:
Design Review
The DMS team examines the charger’s hardware and software design to ensure it meets all requirements in California law and the California Code of Regulations.Performance Testing
The charger is tested under controlled conditions to confirm it measures electricity accurately and consistently across a range of operating scenarios.Labeling and Display Requirements
The display must clearly show the amount of electricity delivered and the total price. Prices must be transparent, easy to read, and free of hidden fees.Fraud Prevention Measures
The charger must include safeguards to prevent tampering or manipulation that could lead to inaccurate billing.Issuing the Certificate of Approval (COA)
If all tests are passed, DMS issues a Certificate of Approval for that charger model. This certificate means any unit of that model can be installed and used for commercial transactions in California.
It’s important to note that CTEP approval applies to the model of charger, not just a single unit. Once a model has been approved, each individual unit still needs to be inspected, tested, and sealed on-site before it can go live.
Your Role as a Station Owner
When you install EV Range chargers, you are the owner and operator of those devices. That means you hold the legal responsibility for keeping them compliant at all times. Even though EV Range provides certified hardware, there are still several steps you must take to meet your obligations.
1. Use CTEP-Approved Hardware
EV Range chargers are already CTEP-certified, which takes care of the first step. This ensures your hardware model is legally approved for commercial use in California.
2. Field Verification and Sealing by an RSA
Before your station can begin billing customers, it must be inspected and sealed by a Registered Service Agency (RSA). The RSA will test the installed charger on-site to confirm it’s functioning properly and matches its CTEP-approved specifications. Once the unit passes, the RSA applies an official seal and submits a Placed-in-Service report to the county.
3. Local County Registration
In California, you must register your charging stations with your County Weights and Measures office at installation or commissioning. This registration allows the county to track inspections, confirm compliance, and schedule annual follow-ups.
4. Documentation Upkeep
You must keep records of your:
RSA seal
Calibration certificate
County registration and permits
These documents must be available upon request during inspections.
5. Annual Inspections
Compliance is not a one-time event. Each year, your station must be retested and resealed by an RSA. Calibration certificates must also be renewed to confirm ongoing accuracy.
Why Annual Inspections Are So Important
Electric vehicle charging stations operate in varied and sometimes harsh conditions. Temperature changes, electrical fluctuations, and software updates can all affect measurement accuracy.
Annual inspections ensure your chargers are still delivering accurate, transparent, and legally compliant measurements. They also help identify potential issues before they become problems for your customers or lead to enforcement action from the county.
Failing to keep up with these inspections can result in fines, mandatory shutdowns, and lost revenue. In some cases, non-compliance can also make you ineligible for incentive programs or grants.
How EV Range Supports You
At EV Range, our job doesn’t stop at delivering the hardware. We work with station owners across California to make sure compliance is built into the process, not left as an afterthought.
Here’s how we help:
Deploy CTEP-Compliant Hardware
Every charger we install in California is already certified for use under CTEP.Deliver Software That Meets Transparency Standards
Our software ensures pricing and energy delivery are displayed clearly, meeting all requirements for accuracy and customer visibility.Guide You Through County Registration and Documentation
We walk you through the steps to register with your County Weights and Measures office and keep all required paperwork organized.Coordinate RSA Field Testing and Sealing
We connect you with qualified Registered Service Agencies and help schedule inspections so you can go live as quickly as possible.Ongoing Compliance Support
Whether it’s your first annual inspection or your fifth, we’re here to answer questions, help arrange testing, and ensure your stations remain in good standing.
Common Compliance Mistakes to Avoid
Many new station owners run into the same pitfalls when trying to get their chargers online. Being aware of these in advance can save you time, money, and frustration.
Assuming CTEP approval is the only step
Having a CTEP-certified charger model is essential, but each unit must still go through RSA inspection and county registration before use.Skipping county registration
Even with all state-level approvals, failing to register with your county’s Weights and Measures department can put you out of compliance.Letting documentation lapse
Expired calibration certificates or missing RSA seals are among the most common compliance violations.Delaying annual inspections
Waiting until the last minute or missing an inspection date can lead to costly downtime.
Resources for Station Owners
If you’re looking for more detailed information, these resources are a good place to start:
Final Thoughts
CTEP compliance is a critical part of operating an EV charging station in California. It protects customers by ensuring they get exactly what they pay for, and it protects you by keeping your business in line with state law.
While the process may seem complex at first, it becomes much more manageable when you know the steps and have a partner who can guide you through them. EV Range is committed to making compliance straightforward, from delivering approved hardware to supporting you through annual inspections.
With the right approach, CTEP compliance doesn’t have to be a hurdle — it can be part of your competitive advantage. Customers trust stations that are transparent, accurate, and professionally maintained, and that trust can help you grow your charging business for years to come.
