Do You Need a Smog Check When Buying or Selling a Car in California?

If a car is changing hands in California, chances are a smog check is part of the deal. But who is responsible for it—the buyer or the seller? What if the car was just tested last year? And do the rules change when the car is a gift from a family member or arrives from another state? Here's everything you need to know about California's change-of-ownership smog requirements.

The Short Answer: The Seller Is Responsible

Under California law, the seller is required to provide the buyer with a valid smog certificate at the time of sale. This applies to most gasoline-powered vehicles more than four model years old. The cost of the inspection is the seller's responsibility unless both parties agree otherwise in writing.

The smog certificate must be dated within 90 days of the sale. If the transfer paperwork isn't completed within that 90-day window, the vehicle will need a fresh inspection before the DMV will process the title transfer.

One Common Misconception: The Biennial Test Doesn't Count

Many sellers assume that if their registration renewal smog check was done recently, they're covered. Not quite. A change of ownership is a separate smog requirement from your regular biennial (every-two-years) inspection. Even if your car passed its renewal smog check 6 months ago, you'll still need a new certificate to sell it—unless that certificate happens to fall within the 90-day window.

Vehicles Exempt from the Transfer Smog Check

Not every sale requires an inspection. The following vehicles are exempt from the change-of-ownership smog check:

• Gasoline vehicles four or fewer model years old — instead of a smog check, the buyer pays a small smog transfer fee to the DMV at registration
• Gasoline vehicles model year 1975 or older
• Electric vehicles (EVs) — no tailpipe, no test
• Motorcycles
• Diesel vehicles model year 1997 or older, or diesels with a GVWR over 14,000 lbs
• Natural gas vehicles over 14,000 lbs GVWR

Note that hybrids are not exempt—they have gasoline engines and follow the same transfer rules as conventional cars. For a full breakdown of which vehicles never need testing, see our guide to smog check exemptions in California.

Family Transfers Are Exempt

Selling or gifting a car to an immediate family member does not require a smog check. The DMV considers the following relationships immediate family for this purpose:

• Spouse or registered domestic partner
• Parent or child
• Grandparent or grandchild
• Sibling

Transfers to more distant relatives—aunts, uncles, cousins, in-laws—are treated like any other sale and do require a smog certificate. Keep in mind the exemption applies to the transfer itself; the new owner will still need to pass the regular biennial smog check when their renewal comes due.

What About Gifted or Inherited Vehicles?

A gifted vehicle follows the same rules as a sale: exempt if it's going to immediate family, otherwise a smog certificate is required. Inherited vehicles transferred through an estate are generally exempt from the transfer smog check as well.

Buying a Car from Out of State

Bringing a vehicle into California from another state? Most gasoline vehicles need a smog check to complete their first California registration, regardless of the vehicle's age — our out-of-state registration guide walks through the full process, including the 20-day deadline. The main exception is a brand-new vehicle with fewer than 7,500 miles on the odometer. Out-of-state vehicles must also be California-certified or federally-certified depending on their mileage when first brought into the state, so it pays to verify emissions compliance before you buy.

Tips for Sellers

• Get the smog check before listing the car. A current certificate reassures buyers and speeds up the sale.
• Use a STAR certified station. Some vehicles are directed by the DMV to test at STAR stations—testing at one ensures the certificate is accepted no matter what.
• Fix known issues first. If the check engine light is on, the car will fail. Learn what happens if your car fails a smog test and address problems before the buyer shows up.
• Keep the certificate with your bill of sale. The DMV records results electronically, but having the paperwork handy avoids delays.

Tips for Buyers

• Ask for the smog certificate and confirm it's dated within 90 days.
• Don't accept "you can smog it later." Once you've paid, a failed test becomes your problem—and repairs can cost far more than the car's paperwork suggested.
• Check the registration status with the DMV before handing over money. Back fees and lapsed registration follow the car, not the seller.

Selling a Car in Pasadena? We Can Help

Lake Smog Test Only is a STAR certified, test-only station in Pasadena—which means we have no incentive to sell you repairs. We test all vehicles, including change-of-ownership inspections, and most tests take about 15 to 20 minutes. Walk-ins are always welcome, and you can grab a coupon before you come in. Questions about whether your sale needs a certificate? Call us at (626) 798-0049 and we'll sort it out in seconds.