California Smog Check When Buying or Selling a Used Car: Who Pays and What's Exempt (2026)

The listing says "runs great, sold as-is, buyer pays smog," the price is a few hundred under everything else on Marketplace, and the seller wants cash tonight. If the car is in California, that smog line should slow you down more than the price. California puts the smog certificate on the seller in most private sales, the certificate expires fast, and a car that fails after you pay can leave you with something you can't register. Here's how the rules read in early October 2026, where the official pages disagree, and how to check a car's smog record before you meet anyone.

Who pays for the smog check

In the ordinary private sale, the seller. The Bureau of Automotive Repair (BAR) says a Smog Check is required before you sell and that you give the buyer a copy of the inspection report. Vehicle Code §24007(b) says the seller must hand over a valid certificate of compliance at or before delivery, and that nobody may sell a used car that isn't emissions-compliant unless it goes to a dealer or to be legally dismantled. We didn't find an as-is exception in that text, so "buyer pays smog" is a negotiating ask, not a rule change.

BAR says station prices aren't regulated, but every passing car carries an $8.25 state certificate fee on top of the shop's price, so call around. A seller who won't spend that before listing is either rushed or already knows something. Honestly, the second one is what should worry you.

The 90-day window and the REG 139 shortcut

BAR says a passing certificate goes to DMV electronically and is valid for 90 days, and §4000.1(d)(1) skips a new test only if the transfer application reaches DMV inside that window. So the date that counts is when the transfer gets submitted, not when you shook hands. If the seller tested on day 80 and you sit on the title for three weeks, the next test may be on you.

If the seller's last smog was for their own registration renewal and the sale falls inside those 90 days, they can give you DMV form REG 139 instead of a fresh test. Under §5751.5 they sign under penalty of perjury that they haven't modified the emissions system. The form also says you can test the car before the deal closes: pass, and you pay for the test; fail, and the seller reimburses you and repairs it at no cost to you before completing the sale. Use that right before money moves.

Newer cars, the transfer fee, and numbers that conflict

BAR lists two different newer-car breaks for gas, hybrid, and alternative-fuel vehicles: eight model years and newer skip the renewal smog, and four model years and newer skip the change-of-ownership smog. The DMV smog page words the transfer rule as "less than four years old" and says the new owner pays a smog transfer fee instead. Diesels get no model-year break. So a six-year-old gas car can be exempt at renewal and still need a certificate when sold, which catches a lot of sellers off guard.

§4000.1(d)(7) sets the transfer fee at $8, matching DMV's current fee table. The renewal-side abatement fee is messier: DMV's fee table lists $20, while DMV's 2019 bulletin and a December 2018 CBS Sacramento report say seven- and eight-model-year-old cars pay $25 a year. Both are probably true for different ages, but check your renewal notice before quoting either. DMV's bulletin also says its system works out exemptions from the transfer date, so treat any model-year math as a guess until DMV confirms it.

Family transfers and out-of-state cars

§4000.1(d)(2) exempts transfers from a parent, grandparent, sibling, child, grandchild, or spouse, and DMV adds domestic partners. Here's the catch: DMV and BAR both say that if a relative bought the car for you without first titling it in their name, a smog check is required. Aunts, cousins, and in-laws aren't on the statute's list.

Cars coming from another state need a California test; DMV's out-of-state registration guide says the certification must come from a California station. The same guide warns that residents generally can't register a car under 2 years old with fewer than 7,500 miles unless it was built to California emissions standards or qualifies for an exemption. A cheap, nearly new "49-state" car from Nevada can become a car you can't plate here.

When it fails, and why "as-is, no smog" is a red flag

In a 2018 NBC Los Angeles report, a buyer couldn't register a 2000 Toyota bought from a dealer because the smog was overdue, and then it failed; the dealer fixed it only after DMV sent an investigator. BAR's page says dealer-sold cars must have passed within the past two years, a different window we couldn't trace to a statute line here. Private sellers have nobody watching, and BAR's Consumer Assistance Program won't bail you out mid-sale: its repair help, up to $1,450 for 1996-and-newer cars, requires a failed biennial check on a car that isn't undergoing a transfer of ownership.

So the blunt version: a seller pushing "no smog, as-is, cash only" on a car that needs one is handing you the repair bill, the registration delay, and maybe a check-engine light they cleared that morning. As-is covers mechanical condition; the certificate is a separate legal duty. We cover the wider trap in why as-is cars still need a history check, and if it smells like a flipper selling under someone else's name, read our curbstoning and title-jumping guide.

Check smog history before you meet

BAR's free inspection history lookup takes a VIN or plate; BAR prefers the VIN because plates change, and records update daily at midnight. Look for fails followed by a pass at a different station, gaps where a test should be, or a pass that doesn't fit the seller's story. Match the VIN to the dash plate and title, because a valid smog on the wrong VIN is worthless.

CARFAX shows emissions results only when they were reported to it. We've seen CARFAX's sample report for a 1997 Tahoe list "Passed emissions inspection" year after year in New York, which helps spot gaps and mileage at each test, but BAR's lookup is the record for a California smog. Our guide to emissions entries on CARFAX explains those lines, and a salvage brand changes things again; see California salvage and rebuilt title rules and why salvage cars fail emissions tests.

No report predicts a dying catalytic converter, so add a pre-purchase inspection, and clear any loan first with our lien guide. Through our site a CARFAX report runs about $5.50 as a guest or $4.50 as a member, and a CARFAX plus AutoCheck bundle about $6.75, versus retail CARFAX often quoted at $39.99 to $44.99; confirm at checkout. We're a licensed reseller, not affiliated with CARFAX, AutoCheck, or Experian, and nobody gives full official reports away free, whatever a pop-up claims.

Other states

None of this carries over. The EPA lists state inspection programs, and test types and sale-time rules vary by state and sometimes county. In May 2026 the EPA proposed approving North Carolina's plan to end emissions testing in its last 19 counties, so check the state's own program instead of assuming California's 90-day seller rule.

Sources

• California BAR: Smog Check requirements
• California BAR: Vehicle inspection history lookup
• California BAR: CAP repair assistance
• California DMV: Smog inspections
• California DMV: Registration fees
• California DMV: VIN 2018-19 abatement fee bulletin (PDF)
• California DMV: REG 139 (PDF)
• California DMV: Registering an out-of-state vehicle (PDF)
• Cal. Vehicle Code §24007
• Cal. Vehicle Code §4000.1
• Cal. Vehicle Code §5751.5
• NBC Los Angeles: Used car that can't pass smog (2018)
• CBS Sacramento: Two extra years before smog (2018)
• CARFAX sample report, 1997 Tahoe (PDF)
• EPA: Vehicle emissions I/M programs
• EPA: North Carolina testing proposal (May 2026)