California Vehicle Bill of Sale: What It Is and How It Works

A bill of sale is a written record of a private vehicle transaction. In California, it documents the transfer of a vehicle from one party to another — who sold it, who bought it, what was sold, and what was paid. It's not a title transfer on its own, but it plays an important supporting role when changing ownership, and in some situations it's the only paper trail proving a sale happened at all.

What a California Vehicle Bill of Sale Actually Does

California doesn't require a separate bill of sale form the way some states do. The state's primary ownership transfer document is the Certificate of Title, and California uses its own title form (REG 227, the Application for Duplicate or Paperless Title) alongside the title itself to handle formal transfers.

That said, a bill of sale still serves real purposes:

It records the agreed sale price, which matters for calculating use tax at registration
It protects the seller by documenting the exact date ownership changed hands
It protects the buyer by confirming what they paid and what vehicle they received
It can serve as supporting documentation if a title is delayed, lost, or disputed
It's often required by lenders, insurers, or storage facilities as proof of purchase

In private-party sales especially, having a signed bill of sale fills gaps that the title alone doesn't cover — like whether the car was sold "as-is," what the odometer read at sale, and whether any known defects were disclosed.

What the California DMV Uses Instead 📄

California has its own built-in ownership transfer mechanism. When a vehicle is sold, the seller is required to:

Sign the back of the title over to the buyer
Submit a Notice of Release of Liability (NRL) to the DMV — typically within 5 days of the sale

The NRL is critical for sellers. It notifies the DMV that the vehicle changed hands, protecting the former owner from liability for parking tickets, tolls, accidents, or other violations that occur after the sale.

Buyers then have a set window — generally 10 days in California — to transfer the title into their name at the DMV and pay any applicable use tax and registration fees.

A bill of sale doesn't replace any of these steps. It supplements them.

What to Include in a California Vehicle Bill of Sale

There's no single mandatory state form for a bill of sale in California, though the DMV does provide Form REG 135 as an optional bill of sale template. Whether you use that form or create your own, the document should include:

Field	What to Include
Seller name and address	Full legal name, current address
Buyer name and address	Full legal name, current address
Vehicle description	Year, make, model, color
VIN	17-character Vehicle Identification Number
Odometer reading	Mileage at time of sale
Sale price	The actual amount paid
Date of sale	Exact date the transaction occurred
Payment method	Cash, check, etc.
As-is acknowledgment	If applicable
Signatures	Both buyer and seller

The VIN and sale price are the two fields that matter most from a DMV and tax standpoint. The sale price is used to calculate California use tax, which is collected at the time of registration. If no price is listed or the price seems below market, the DMV may assess tax based on the vehicle's fair market value instead.

When a Bill of Sale Becomes More Important 🔑

In most standard private sales, the title does the heavy lifting. But a bill of sale carries more weight in specific situations:

Gifted vehicles: California has specific rules around gifted vehicles, including an affidavit of non-commercial transfer. A bill of sale noting "$0" or "gift" supports that process but isn't the full picture on its own.

Missing or delayed titles: If a title isn't immediately available, a bill of sale documents the transfer while the title issue is resolved — though the DMV will still require a valid title to complete registration in the buyer's name.

Older or non-titled vehicles: Very old vehicles in California (generally pre-1976) may use a Bill of Sale as the primary ownership document rather than a title. This varies based on year and vehicle type.

Bonded title situations: If a buyer can't obtain a title at all, California has a bonded title process. A bill of sale is one of the supporting documents used to establish the ownership chain.

Commercial or fleet transactions: More formal documentation is typically expected, and a bill of sale provides an auditable record.

What Varies by Situation

Even within California, outcomes differ based on several factors:

Vehicle type — motorcycles, trailers, off-highway vehicles, and commercial trucks each follow slightly different documentation paths
County — smog check requirements and some fee structures vary by county
Vehicle age — older vehicles may be exempt from smog or have different title rules
Lien status — if a loan is still attached to the vehicle, the lender typically holds the title, and additional steps are required before a clean transfer can happen
Purchase price relative to market value — affects how use tax is assessed