CARB Compliance in California: Clean Truck Check, Fees, Penalties

CARB compliance in California means meeting the California Air Resources Board’s rules for any diesel vehicle with a gross vehicle weight rating over 14,000 pounds that operates on state roads. As of March 10, 2026, that comes down to four things: your engine must be model year 2010 or newer, your vehicle must be registered in the Clean Truck Check Vehicle Inspection System (CTC-VIS), you must pay the $32.13 annual compliance fee, and you must submit passing emissions tests on the schedule set for your vehicle.¹² Miss any of it and the DMV can block your registration while daily penalties accrue.

Which Vehicles Are Covered

The rule reaches on-road diesel trucks and buses with a gross vehicle weight rating above 14,000 pounds. Since January 1, 2023, every diesel vehicle in that weight class operating in California has needed a 2010 or newer model year engine and emission system, with very few exceptions.³ Registration state doesn’t matter. If the truck is on a California public road, it’s in scope.

Transport refrigeration units and off-road diesel equipment (construction machinery, industrial vehicles) fall under separate CARB regulations with their own reporting systems and are not covered by Clean Truck Check.

The Three Clean Truck Check Steps

Clean Truck Check replaced the older TRUCRS portal used for the Truck and Bus Regulation. If you filed there before, you now work through CTC-VIS instead. The program has three requirements: report your vehicle, pay the fee, and submit a passing emissions test.¹

Report in CTC-VIS

Start by creating an Entity or Tester Account on the CTC-VIS portal. You’ll need the vehicle’s seventeen-digit VIN, which is the primary identifier CARB uses across its filings. You’ll also need the engine serial number and engine family name, both printed on the emission control label fixed to the engine by the manufacturer. The label must be legible and in its original location.⁴

Copy the engine family name exactly as it appears. A single transposed character creates a mismatch that will hold up your compliance status. You’ll also report the gross vehicle weight rating and the state the vehicle is registered in.

Pay the Annual Fee

The compliance fee is $32.13 per vehicle as of January 1, 2026.² It’s billed through CTC-VIS and tied to the VIN.

Submit a Passing Emissions Test

Tests must be performed by an authorized tester and uploaded through CTC-VIS. The method depends on the engine, not just the model year.

OBD-equipped diesel engines, 2013 and newer: a scan of the on-board diagnostics data using a CARB-approved OBD testing device.
OBD-equipped alternative fuel engines, 2018 and newer: the same OBD scan process.
Non-OBD diesel engines, 2012 and older: an SAE J1667 smoke opacity test plus a visual inspection of the emission control equipment.
Non-OBD alternative fuel engines, 2017 and older: a visual inspection of the emission control equipment.
Off-road engines of any model year: opacity test and visual inspection, regardless of whether OBD is present.

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Older engines fail most often on opacity, and the cause is usually deferred injector or turbocharger work. Keeping maintenance current is the most reliable way to pass.

Testing Deadlines

Most vehicles must complete compliance twice per year in 2026. For California-registered vehicles, the two deadlines are your DMV registration expiration date and six months after that date. For out-of-state vehicles, deadlines run off the last digit of the VIN, with each digit assigned a month and a six-month repeat cycle.⁶

Agricultural vehicles and California-registered motorhomes used for recreation or emergency occupancy follow an annual schedule. Starting in October 2027, testing frequency for OBD-equipped vehicles increases to four times per year, while agricultural vehicles and motorhomes stay annual.⁵

The Low-Use Exemption

Vehicles that rarely operate in California may qualify for a permanent low-use exemption. The vehicle must average 200 or fewer hours of operation per year, or accumulate fewer than 600 hours over a rolling three-year period.⁷ Go over the 200-hour annual cap and you’re in violation, so track hours carefully. The exemption is worth knowing about for specialty equipment and trucks that only enter California for occasional work.

If Your Truck Is Registered Outside California

Registering elsewhere does not exempt you. Any heavy-duty vehicle operating on California public roads has to report in CTC-VIS, pay the annual fee, and submit passing emissions tests.⁶ CARB will not accept an emissions test performed in another state in place of its own. Smaller interstate carriers making occasional California deliveries are the most common group caught out by this.

Broker and Freight Contractor Duties

Compliance is not just the truck owner’s problem. Freight contractors must only hire compliant vehicles, and brokers must only arrange shipments through motor carriers whose vehicles are in compliance.⁸

Before dispatching a load, verify compliance one of two ways: pull the vehicle’s individual compliance certificate from CTC-VIS (valid at the time of dispatch), or obtain an Affirmation of Fleet Wide Compliance issued within the past 12 months. Compliance attaches to the VIN, not to the business name or license plate on the certificate.⁸

Keep verification records and carrier contact information for at least five years from the hire date, and be ready to produce them within 72 hours if CARB inspectors ask.⁸ One carve-out: these verification duties don’t apply when a vehicle is delivering goods or providing services directly to a facility as the end consumer.

What Non-Compliance Costs

CARB enforcement runs on three tracks: criminal and civil penalties, DMV registration holds, and roadside inspection.

Under California Health and Safety Code Section 42400, violating a CARB rule is a misdemeanor punishable by a fine of up to $5,000, up to six months in county jail, or both. Each day a violation continues counts as a separate offense. On the civil side, Section 39674 sets strict liability of up to $1,000 per day for standard violations. Violations touching certain federally delegated air quality rules cap at $10,000 per day. Negligent emissions can trigger penalties up to $25,000 per day, and knowing violations with actual health impacts can reach higher still.

Fleet-wide actions produce the largest numbers in practice. When CARB finds a pattern across multiple vehicles, settlement talks usually involve detailed audits of maintenance and operating records, and companies with dozens of non-compliant units have faced settlements in the hundreds of thousands of dollars.

DMV Registration Holds

The consequence most owners actually run into first is a DMV block. Since January 1, 2020, the DMV has had to verify that heavy-duty diesel vehicles comply with the Truck and Bus Regulation before registering or renewing them.⁹ A flagged vehicle can’t be legally registered or operated on public roads until the problem is cleared. Clean Truck Check has its own DMV hold mechanism under SB 210 that applies the same approach to current compliance requirements.

Roadside Enforcement

State inspectors run audits at weigh stations, commercial hubs, and random roadside stops. They check for valid compliance certificates and verify that the physical engine matches the data reported in the system. A mismatch between the engine in the truck and the engine family name on file can produce an immediate citation and open a broader review of your fleet.

Zero-Emission Purchase Rules Coming Next

Beyond keeping current diesel engines compliant, California is phasing in zero-emission vehicle purchase requirements through the Advanced Clean Fleets regulation.

High-priority fleets began facing requirements on January 1, 2024. A fleet qualifies as high-priority with $50 million or more in gross annual revenue, or by owning or directing 50 or more vehicles operating in California. Federal government fleets are also included. These fleets must begin buying ZEVs as part of their normal replacement cycles.¹⁰

Drayage trucks at California ports and intermodal rail yards face the tightest schedule. Any new drayage truck added to a fleet since 2024 must be a ZEV, and all drayage trucks must be zero-emission by 2035. Trucks over 18 years old or past 800,000 miles must come out of service. State and local government fleets follow their own ZEV milestone schedule under a separate compliance pathway.¹¹

1
California Air Resources Board. CTC-VIS
2
California Air Resources Board. Clean Truck Check Compliance Fee Update Effective 1/1/2026
3
California Air Resources Board. Truck and Bus Regulation
4
California Air Resources Board. Engine Label or Emission Control Label (ECL)
5
California Air Resources Board. Clean Truck Check – Emissions Compliance Testing Requirements
6
California Air Resources Board. Clean Truck Check – FAQ
7
California Air Resources Board. Fact Sheet: Low-Use Requirements
8
California Air Resources Board. Clean Truck Check Requirements – Freight Contractor, Broker
9
California Air Resources Board. SB 1 Report
10
California Air Resources Board. Advanced Clean Fleets
11
California Air Resources Board. Advanced Clean Fleets Regulation – ZEV Milestones Option