Smog Plus is a third-party service that handles smog checks and registration paperwork for you

Smog Plus is a private company that processes smog inspections and submits the results directly to the California DMV on your behalf. Instead of visiting a smog station yourself and then going to the DMV, you can use Smog Plus to manage both steps. The service is available in California only, where smog checks are required for most vehicles before registration renewal.

The core transaction is straightforward: you schedule an inspection at a Smog Plus location, the technician tests your vehicle, and if it passes, Smog Plus files the results electronically with the DMV. You do not have to carry paperwork between the smog station and the DMV yourself. For vehicles that fail, Smog Plus can also help you understand what repairs are needed before a retest.

Smog Plus charges a fee on top of the state smog check fee. The smog inspection itself costs the same whether you go to Smog Plus or any other Bureau of Automotive Repair (BAR) certified station — the state sets that price. Smog Plus adds its own service charge for handling the DMV filing and coordination.

Key Takeaways

  • Smog Plus is a private company that runs smog inspections and files results with the DMV, so you do not have to visit two separate locations.
  • The state smog inspection fee is the same at any BAR-certified station, but Smog Plus charges an additional service fee for DMV filing.
  • You must schedule an appointment at a Smog Plus location; walk-ins are not accepted at most sites.
  • Smog Plus works only in California and only for vehicles that require smog checks under state law.

When you need a smog check before DMV renewal

California requires a smog check before you can renew your vehicle registration if your car is more than four years old. Trucks and motorcycles have different rules — some are exempt, and others require checks on different schedules. The DMV will not process your registration renewal without a passing smog inspection report on file.

If your vehicle is due for renewal and you have not had a smog check in the past 90 days, you must get one before the DMV will accept your renewal. Smog Plus can schedule that inspection and file the results, which means your registration paperwork can move forward without you making a separate trip to a smog station.

How to use Smog Plus for your registration renewal

Start by finding a Smog Plus location near you on their website or by phone. You will need to schedule an appointment — most locations do not accept walk-ins. When you call or book online, have your vehicle's license plate number and VIN ready, along with your driver's license.

On the day of your appointment, bring your vehicle and your driver's license. The technician will run the smog test, which takes about 30 minutes. If your vehicle passes, Smog Plus files the inspection report with the DMV electronically. You can then renew your registration online through the DMV website, by mail, or at a DMV office — the smog results will be in the system.

If your vehicle fails the smog test, Smog Plus will tell you what failed and what repairs are typically needed. You will need to have those repairs done at a repair shop, then return to Smog Plus or another BAR-certified station for a retest. The retest fee is usually lower than the initial inspection fee.

Smog Plus fees and what they cover

The state-mandated smog inspection fee varies by vehicle type and location, but typically ranges from $30 to $50 for a standard passenger car. This fee is the same at any BAR-certified station, including Smog Plus. Smog Plus then charges its own service fee on top of that for handling the DMV filing and coordination — this additional fee varies by location and service level.

Some Smog Plus locations offer a "Smog Plus Premium" service that includes additional benefits like same-day results or priority scheduling. These premium options cost more than the standard service. Ask about the total cost — both the state inspection fee and the Smog Plus service fee — before you schedule.

The fee covers the inspection itself and the electronic filing with the DMV. It does not cover any repairs your vehicle may need if it fails the test. Repairs are done separately at a repair shop of your choice, and you pay that shop directly.

Alternatives to Smog Plus for your smog check

You can visit any Bureau of Automotive Repair (BAR) certified smog station in California. These include independent smog shops, some gas stations, and some repair shops. The inspection fee is the same everywhere — the state sets it. The difference is that at a non-Smog Plus station, you receive a paper inspection report that you must then take to the DMV or submit yourself online.

If you renew your registration online through the DMV website, you can upload a photo of your smog inspection report, so you do not have to visit a DMV office in person. This option is free and works with any BAR-certified inspection, not just Smog Plus. The trade-off is that you handle the paperwork yourself rather than having Smog Plus do it for you.

Some repair shops offer smog checks as part of a larger service package. If you are already planning repairs, bundling the smog check with that work can save you a trip. However, you still pay the same state inspection fee.

What happens if your vehicle fails the smog test

A failed smog test means your vehicle did not meet California's emissions standards. The inspection report will list which emissions systems failed — typically the oxygen sensor, catalytic converter, or engine control system. You cannot renew your registration until you fix the problem and pass a retest.

You have the option to take your vehicle to any repair shop, not just the Smog Plus location where it failed. Some shops specialize in emissions repairs and may charge less than a dealership. Get a repair estimate before committing, because some repairs can be expensive. After repairs are complete, you can return to any BAR-certified station for a retest.

California offers a Smog Check information Program in some counties for low-income vehicle owners. If you may have access to, the program may cover part or all of the repair costs. Contact your county's air quality management district to learn whether your county participates and what the income limits are.

Frequently Asked Questions

Can I renew my registration without a smog check?

Only if your vehicle is exempt. Vehicles less than four years old, electric vehicles, and some motorcycles do not require smog checks. The DMV will tell you whether your vehicle needs one when you start the renewal process online or at an office.

How long does a Smog Plus inspection take?

The actual test takes about 30 minutes. If you schedule an appointment, you will not wait in line. Smog Plus files the results with the DMV the same day, so you can renew your registration when ready after.

What if I move out of California after my smog check but before I renew?

You can still renew your California registration online or by mail using the smog results Smog Plus filed. You do not have to be in California to complete the renewal. However, if you register your vehicle in another state, you will need to follow that state's rules, which may be different.

Does Smog Plus work with the DMV online renewal system?

Yes. Once Smog Plus files your inspection results with the DMV, you can renew online at dmv.ca.gov. The smog results appear in your DMV record within one business day, and you can complete renewal without visiting an office.

What if my vehicle fails and I need a retest?

You can return to Smog Plus or visit any other BAR-certified station for the retest. The retest fee is typically $10 to $15, less than the initial inspection. You have 30 days from the original test to retest before you have to start the inspection process over.