Smog Checks, Title and Registration When Buying a Used Car in California

By Bancroft Auto Sales, LLC · Updated September 23, 2026 · 4-minute read

Paperwork is the part of buying a car that most people dread. In California, a used car purchase involves smog certification, a title transfer, registration, license plates, taxes and fees. The good news is that when you buy from a licensed dealer, much of this work is handled for you. This guide from Bancroft Auto Sales in San Diego explains how each piece works so you know what to expect.

Rules and fees can change, so for the most current details, check the California DMV and the Bureau of Automotive Repair websites.

Smog Certification Basics

Why Smog Checks Matter

California’s Smog Check program helps reduce air pollution by making sure vehicles’ emissions systems are working properly. Many vehicles need a smog check every two years at registration renewal, and a valid smog certification is also generally required when a vehicle changes ownership.

Smog Certification When a Car Is Sold

For most used vehicle sales in California, the seller is responsible for providing a valid smog certification. A smog certificate is generally valid for 90 days from the date of the inspection for a change of ownership. When you buy from a dealer, the dealer is responsible for making sure a valid smog certificate is in place for vehicles that require one. When you buy from a private party, the seller should provide it.

Common Exemptions

Some vehicles are exempt from the change-of-ownership smog requirement. Examples commonly include older gasoline vehicles from model year 1975 and earlier, electric vehicles, and certain diesel and heavy vehicles. Newer vehicles, generally those four model years old or newer, may be exempt from the transfer smog check but pay a smog transfer fee instead. Because exemptions have specific conditions, check the DMV or Bureau of Automotive Repair for the rules that apply to a particular vehicle.

If a Car Fails Smog

A vehicle that fails a smog check needs repairs before it can pass. This is one reason it is important that smog certification is handled before a sale is completed, so the buyer is not left with a car that cannot be registered.

Title Transfer

The Certificate of Title, often called the pink slip, shows who legally owns a vehicle. When a vehicle is sold, ownership must be transferred to the new owner. If there is a loan on the vehicle, the lender is listed as the legal owner or lienholder until the loan is paid off.

When you buy from a dealer, the dealer collects the necessary documents and submits the transfer to the DMV. When you buy privately, the buyer and seller complete the title transfer themselves, and the seller should also notify the DMV of the transfer so they are not responsible for the vehicle afterward.

Registration and License Plates

Buying From a Dealer

California dealers typically process registration for vehicles they sell and collect the related fees as part of the purchase. Dealers issue temporary license plates at the time of sale, so you can legally drive while the DMV processes your registration and permanent plates or registration documents are delivered.

At Bancroft Auto Sales, our vehicles are delivered fully registered with the requirements completed, which means you do not need to make a separate trip to the DMV to finish the process.

Buying From a Private Seller

In a private sale, the buyer is usually responsible for submitting the paperwork and paying transfer fees and use tax to the DMV within the required time after purchase. Missing deadlines can lead to penalties.

Taxes and Fees to Expect

The total cost of a used car in California includes more than the vehicle price. Typical items include:

  • Sales or use tax: Generally based on the tax rate where the vehicle will be registered, which is usually your home address.
  • Registration fees: Including the base registration fee and other state and local fees.
  • Vehicle license fee: A fee based on the vehicle’s value.
  • Title transfer fee: For recording the change of ownership.
  • Smog-related fees: Such as a smog transfer fee for exempt newer vehicles.
  • Dealer document processing fee: A fee dealers may charge for preparing paperwork, which is regulated in California.

From October 1, 2026, California’s CARS Act requires dealers to clearly disclose the total price of a vehicle during advertising and negotiations. Taxes and government fees are typically listed separately. Learn more in our article on the CARS Act and the 3-day right to cancel.

Insurance Before You Drive

California requires drivers to carry at least the minimum liability insurance. You will need proof of insurance before driving your newly purchased car home. If you are financing, your lender will usually require comprehensive and collision coverage as well. Contact your insurance provider before your purchase to add the new vehicle.

Registration Renewal After Purchase

Registration must be renewed every year. The DMV mails renewal notices in advance, and your notice will tell you whether a smog check is required that year. Keep your address current with the DMV so you receive notices on time.

Paperwork Checklist for Buyers

  • Valid driver’s license
  • Proof of insurance
  • Signed purchase contract and financing documents
  • The Buyers Guide for the vehicle
  • Temporary plates and registration paperwork from the dealer
  • Copies of the smog certificate if applicable
  • Trade-in documents, if you traded a vehicle

Frequently Asked Questions

Who pays for the smog check when I buy from a dealer?

In most California sales, providing valid smog certification is the seller’s responsibility. When you buy from a dealer, the dealer is responsible for smog certification on vehicles that require it.

How long is a smog certificate valid for a sale?

A smog certificate is generally valid for 90 days for a change of ownership.

Do I need to go to the DMV after buying from a dealer?

Usually not. Dealers typically submit the title and registration paperwork for you. Our vehicles are delivered fully registered.

Buy With Less Paperwork Stress

Paperwork should not stand between you and your next car. At Bancroft Auto Sales, we handle the registration requirements so you can focus on choosing the right vehicle. Browse our used cars, start your online credit application, or contact us with any questions about the process.

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