How Do I Register My Diesel Vehicle With CARB?

If you own a diesel truck over 14,000 pounds GVWR that operates on California roads, you're required to register it with CARB through the Clean Truck Check Vehicle Inspection System — known as CTC-VIS. This applies whether you're an owner-operator with a single truck or a fleet manager with dozens. It also applies even if your truck is registered in another state — if it runs on California roads, you need to be in the system.

The registration itself is straightforward — usually about 15 minutes per vehicle. But the process has enough small details that one missed step can lead to DMV registration holds, fines, or rejection at port and rail entry. Here's exactly how to do it right.

Step 1: Confirm your vehicle is subject to Clean Truck Check

Before you create an account, confirm your vehicle is actually in scope. Clean Truck Check applies to nearly all non-gasoline heavy-duty vehicles with a GVWR over 14,000 pounds operating on California public roads — including:

• Commercial diesel trucks (Class 4 and heavier)
• Diesel and alternative fuel motorcoaches and buses
• Hybrid heavy-duty vehicles
• School buses, shuttle buses, transit buses
• California-registered diesel motorhomes
• Government vehicles (federal, state, local)
• Personal-use diesel vehicles over the weight threshold
• Single-vehicle fleets (one truck, one owner)
• Vehicles registered outside California that operate on California roads

Vehicles not subject to Clean Truck Check include gasoline-powered vehicles (those still go through California's regular Smog Check program), out-of-state motorhomes, and vehicles under 14,001 pounds GVWR.

Step 2: Gather what you'll need before logging in

The registration form will ask for very specific information. Having it ready before you start makes the process much faster, especially if you're entering multiple vehicles. For each vehicle, you'll need:

• VIN — must match exactly what's on the DMV registration. A single wrong digit can cause registration holds later.
• License plate — or you can enter "license plate not yet received as of [date]" if waiting on plates
• Engine model year — important: the engine model year can be different from the vehicle model year. Check the emissions control label under the hood.
• GVWR — from the door jamb sticker or registration
• Fuel type — diesel, CNG, LNG, propane, hybrid, etc.
• Make and model

You'll also need entity information — the legal business name, address, and contact info for whoever owns or operates the vehicle. If you're an owner-operator, that's typically you personally. For a fleet, that's your company.

Step 3: Create your CTC-VIS account

Go to cleantruckcheck.arb.ca.gov and click Register. You'll be prompted to enter:

1. A valid email address — this becomes your username permanently, so use one you'll have long-term access to. CARB will send compliance deadlines, NST notices, and other official notifications here.
2. Entity information — legal business name, address, EIN if applicable. Choose the correct entity type (Individual, LLC, Corporation, Government Agency, etc.) carefully — this affects how CARB processes your account.
3. Certification checkbox — you'll certify that the information entered is accurate. This matters because data entry errors get blamed on you later, not CARB.

Once submitted, CARB will email you to confirm the account is active.

Step 4: Add each vehicle to your account

Once logged in, navigate to Add Vehicle within your entity account. Repeat this step for every vehicle in your fleet. For each, enter the data you gathered in Step 2.

Pay particularly close attention to:

• VIN accuracy — CARB transmits a compliant VIN list to the DMV nightly. If your CTC-VIS VIN doesn't match the DMV VIN exactly, your registration will be held.
• Engine model year vs. vehicle model year — these determine whether your vehicle needs an OBD test or a smoke opacity test. A 2014 truck with a 2012 engine, for example, follows older test rules.
• License plate or temporary plate — update this in CTC-VIS as soon as you receive permanent plates, even if your initial entry was temporary.

Step 5: Pay the annual compliance fee

For each registered vehicle, CARB charges an annual compliance fee. For 2026, this fee is $32.13 per vehicle — adjusted from $31.18 in 2025 to account for the California Consumer Price Index.

Payment methods accepted:

• Credit or debit card
• eCheck (bank account routing and account number)

Paper checks are not accepted, and payments made through any other CARB portal or mailed do not count. The fee must be paid through the CTC-VIS interface itself.

Your vehicle's compliance deadline is based either on the DMV registration expiration date (for California-registered vehicles) or the last digit of the VIN (for out-of-state vehicles and California-exempt plates). You can find each vehicle's specific deadline inside your CTC-VIS account.

Step 6: Schedule and submit your passing emissions test

Registration alone isn't compliance. Once your account is set up and the fee is paid, you must also submit a passing emissions test by your assigned deadline. In 2026, most vehicles are subject to semi-annual testing — that's twice per year. Motorhomes and qualifying agricultural vehicles test once per year.

(Starting October 2027, the testing frequency increases to four times per year — but only for vehicles equipped with On-Board Diagnostics systems. CARB will continue to show your specific deadlines in CTC-VIS.)

The test required depends on engine model year:

• 2013 and newer engines (diesel) / 2018 and newer (alternative fuel) — OBD plug-in test
• 2012 and older engines — smoke opacity test plus visual emissions control inspection

Both must be performed by a CARB-credentialed tester. The tester submits passing results directly to CTC-VIS on your behalf — you don't upload them yourself. You can perform the test up to 90 days before your deadline, which gives you a buffer to make repairs if you fail the first time.

What happens if you skip registration or miss a deadline

Non-compliance isn't a parking ticket — the consequences are immediate and operational. If you skip or miss CARB compliance, you may face:

• DMV registration holds — California will not renew your truck's registration until CARB shows you as compliant
• Roadside enforcement — CHP and CARB are authorized to verify compliance at any stop. Remote emissions monitoring devices (REMD) and automated license plate readers (ALPR) are deployed statewide
• Denial of port and railyard entry — non-compliant vehicles can be turned away from California ports and rail terminals
• Notice to Submit to Testing (NST) — if your vehicle is flagged as a potential high emitter, you'll receive an NST and have 30 days to submit a passing test or face penalties
• Citations and fines — CARB has enforcement authority and is using it actively in 2026 and 2027

Common registration mistakes that trigger compliance issues

Over the past two years, the same handful of mistakes have caused most CTC-VIS registration headaches. Watch for these:

VIN typos. A single wrong character means CARB can't match your record to the DMV. Always verify the VIN against the actual title or registration document, not from memory.

Wrong engine model year. Easy to assume the engine year matches the truck year, but they often differ — especially in glider kits, re-powered trucks, or older chassis with newer engines. Check the emissions control label.

Using a personal email for a business account. If your employee leaves, CARB notifications go to a dead inbox and you miss deadlines. Use a business or shared email you'll have long-term access to.

Forgetting to update license plates. Temporary plate placeholders need to be updated to the real plate when received. This isn't automatic.

Treating registration as a one-time task. Registration enrolls your vehicle. Compliance requires ongoing fee payments and emissions tests on the schedule CARB assigns. Mark your deadlines.

A few common questions about CARB registration

Can I register a truck before I have license plates? Yes. CTC-VIS accepts temporary license plates or the placeholder "license plate not yet received as of [date]." Update with the permanent plate once received.

What if my truck is registered out of state but operates in California? You still need to register and comply. Out-of-state registration does not exempt you from Clean Truck Check.

Can I pay the compliance fee with a paper check? No. CARB accepts only credit/debit cards and eChecks through the CTC-VIS portal. Any other payment method does not count toward compliance.

What if I sell or retire a truck mid-year? Update your CTC-VIS account to remove or transfer the vehicle. Fees paid for a sold vehicle are not refunded, but you avoid ongoing compliance obligations.

Do I have to perform the inspection myself? No — most fleet and owner-operators use a CARB-credentialed tester (a station, mobile unit, or qualified mechanic). You can become credentialed yourself by completing CARB's free online training, but most fleets find it easier to outsource testing.

For questions specific to your fleet, CARB's enforcement help email is hdim@arb.ca.gov. They generally respond within a few business days.

The bottom line

CARB registration for diesel and heavy-duty vehicles isn't optional, and the consequences for skipping it are operational, not just paperwork. The good news: the registration itself is straightforward, the annual fee is small ($32.13 per vehicle in 2026), and finding a credentialed tester is easy if you live or operate near a CARB station.

If you're in or near Simi Valley and need a Clean Truck Check inspection, we can help. We're a CARB-credentialed Clean Truck Check station and we submit results to CTC-VIS for you, so you don't have to manage the upload step yourself. Call us at (805) 526-9716 or drive in to 2405 Sycamore Dr.