CA DMV Bill of Sale Form: A Complete Guide to California's Vehicle Sale Documentation
When you buy or sell a vehicle in California, paperwork matters. A lot. The CA DMV bill of sale form sits at the center of that process — not always required by law the way a title transfer is, but often essential for protecting both parties and smoothing the transaction. Understanding what it is, when you need it, what it must contain, and how it interacts with other California DMV documentation is the difference between a clean transfer and a dispute that drags on for months.
This guide covers that full picture — how California approaches vehicle sale documentation, what the bill of sale actually does, and what variables in your specific situation will shape exactly how the process plays out.
What a Bill of Sale Is — and Where It Fits in California's Title Process
A bill of sale is a written record that documents the transfer of ownership of a vehicle from one party to another. It captures the basics: who sold it, who bought it, what was sold, when, and for how much. Think of it as a receipt with legal weight.
In California, vehicle title and documentation involves several overlapping forms. The Certificate of Title (the pink slip) is the primary legal document that proves ownership — and transferring it is mandatory. The DMV bill of sale, by contrast, serves a supporting role. It doesn't replace the title, but it creates a paper trail that protects both the buyer and the seller when questions arise later.
California's DMV uses REG 135 as its official bill of sale form for vehicle transactions. This form is publicly available through the DMV and is designed specifically for private-party vehicle sales — cars, trucks, motorcycles, and certain other registered vehicles. It's straightforward but specific: it captures the vehicle identification number (VIN), year, make, model, odometer reading, sale price, and the signatures of both buyer and seller.
Why California Treats This Differently Than Other States 🗂️
State rules on bills of sale vary significantly. Some states make a bill of sale mandatory for title transfer. California takes a somewhat different approach: the title (or a properly completed Title Transfer section on the pink slip) is what drives the DMV's ownership records, and a bill of sale is not always legally required to complete that transfer.
That said, California strongly recommends — and many situations practically demand — a bill of sale even when it isn't technically required. The reasons are practical:
For sellers, a signed bill of sale with the sale date creates a clear record that you no longer own the vehicle. California requires sellers to notify the DMV of a vehicle sale within five calendar days using a Notice of Transfer and Release of Liability (NRL), which can be submitted online. If a new owner drives the car without re-registering it and gets a ticket, you want documentation of when you stopped being the owner. A bill of sale supports that record.
For buyers, the bill of sale documents the agreed price — which matters for calculating use tax owed during registration. California charges use tax on private vehicle sales based on the purchase price, and the DMV may compare what's reported on the registration paperwork against a bill of sale if there's a discrepancy.
For both parties, a bill of sale provides a point of reference if there's any post-sale dispute about what was agreed to, what condition was disclosed, or what the transaction actually covered.
What the REG 135 Form Captures — and What It Doesn't
California's REG 135 is a single-page form that's deliberately simple. Required fields typically include:
- The seller's name and address
- The buyer's name and address
- The vehicle's year, make, model, body style, and color
- The VIN
- The odometer reading at the time of sale
- The sale price
- The date of sale
- Signatures from both buyer and seller
What REG 135 doesn't do is replace the odometer disclosure requirement for vehicles under a certain age (federally required for vehicles less than 20 model years old), nor does it substitute for the title itself. For newer vehicles, the odometer disclosure is typically made directly on the title — the bill of sale may reflect it as well, but the title entry is the one that counts with the DMV.
The form also doesn't include space for detailed condition disclosures, warranty disclaimers, or as-is language — though some buyers and sellers add a separate written agreement covering those points. California is a "buyer beware" state for used vehicle sales in many respects, but sellers who misrepresent a vehicle's condition can still face legal exposure regardless of what's on the bill of sale.
When You Might Use a Different Format
REG 135 is the DMV's official form, but California does not require that buyers and sellers use it exclusively. A privately written bill of sale that contains all the necessary information — names, addresses, VIN, sale price, date, odometer, signatures — can serve the same legal purpose in most situations.
Some scenarios where format matters more than others:
🔑 Gifted vehicles: When a vehicle changes hands as a gift rather than a sale, the "purchase price" field becomes complicated. Some families write $0 or nominal amounts. Others use a separate gift letter. California has specific rules around how use tax is assessed on gifted vehicles, and the documentation you create at the time of the gift will matter if the DMV has questions.
Vehicles sold as parts or non-operational: If a vehicle is sold without a valid title — for parts, as salvage, or in other non-standard circumstances — a bill of sale may be the primary documentation available, but the DMV process for transferring ownership of a vehicle without a title involves additional forms and procedures that go beyond a bill of sale alone.
Dealer sales: Licensed California dealers operate under a different documentation framework entirely. REG 135 and the standard private-party bill of sale process apply to private-party transactions — person to person. Dealer-issued purchase agreements and contracts serve the bill of sale function in that context, and they typically include considerably more detail.
Commercial vehicles and trailers: Heavier trucks, commercial vehicles, and certain trailers may have additional documentation requirements. Vehicle weight, GVWR, registration class, and use type all affect what paperwork applies — another reason "it depends on your situation" is not a dodge but an honest answer.
How the Bill of Sale Connects to the Broader Title Transfer Process ⚖️
Understanding the bill of sale means understanding where it sits in the sequence of a California vehicle transfer. The typical steps in a private-party sale look something like this:
The seller completes the transfer section on the back of the title (or provides a separate Odometer Disclosure Statement if required), signs it over to the buyer, and hands over the pink slip. Both parties complete REG 135 or a comparable bill of sale. The seller submits the Notice of Transfer and Release of Liability to the DMV — ideally the same day, and no later than five calendar days after the sale. The buyer then has a defined window (typically 10 days in California, though this should be confirmed with current DMV guidance) to submit the title and appropriate fees to transfer registration into their name.
The bill of sale is a document the buyer holds as a record and may need to present during registration — particularly if the DMV questions the reported sale price for use tax purposes. It's not typically submitted to the DMV directly, but having it ready matters.
Variables That Shape the Process
No two vehicle transactions are identical, and several factors determine exactly what documentation you need and how the process unfolds:
Vehicle type and age affect odometer disclosure requirements and which forms apply. Sale price affects use tax calculations — and significantly lowballing the reported price on DMV paperwork while having a different number on the bill of sale creates a paper trail contradiction that can cause problems. Whether a lien exists on the vehicle is a major variable: selling a car with an outstanding loan requires lender involvement to release the lien before a clean title can be transferred. A bill of sale can't resolve a lien situation on its own.
Whether the vehicle has a smog exemption or smog requirement affects what the buyer can do after purchase. California requires smog certification on most vehicles as part of a private-party sale — certain newer vehicles and diesel vehicles are exempt or follow different rules. The bill of sale doesn't capture smog status, but the overall transaction is incomplete without addressing it.
🔍 The seller's and buyer's respective situations — whether either party is a non-resident, whether the vehicle was inherited, whether it's coming from out of state — each introduce additional documentation layers that interact with but aren't replaced by the bill of sale.
Key Subtopics Worth Exploring Further
Several specific questions naturally branch off from this foundation, each with enough nuance to warrant deeper treatment on its own:
The Notice of Transfer and Release of Liability is the seller's primary legal protection after a sale, and understanding how it works — and what happens if you miss the five-day window — is essential for anyone selling a vehicle in California. The bill of sale supports your NRL submission but doesn't substitute for it.
Use tax on private vehicle sales is a source of confusion for many California buyers. The amount owed is typically based on the sale price, collected during registration, and calculated at the county rate where the buyer registers the vehicle. Buyers who register a vehicle for a price that seems implausibly low compared to market value may find the DMV applies a minimum standard value for tax purposes.
What to do when the title is missing or has problems is a situation more common than most people expect — a lost title, a title with a lienholder who's been paid off but never released, or a title from another state. Bills of sale become particularly important in these situations because they document the transaction even when the title documentation is incomplete, but additional steps through the DMV (bonded title process, court-ordered titles, Heirship Affidavits in estate cases) will still be required.
As-is disclosures and condition documentation beyond what REG 135 captures matter for anyone buying a high-mileage or mechanically uncertain vehicle. What's disclosed in writing at the time of sale shapes what recourse (if any) exists if problems emerge later.
The California DMV's official website and published guides are the authoritative source for current form versions, fee schedules, and process requirements — both of which can and do change. The REG 135 form itself is updated periodically, and using a current version matters.