California bill of sale form - RVs, trailers, cars: when you need one

California’s official bill of sale is Form REG 135, a one-page form published by the DMV. California does not legally require a bill of sale to transfer a vehicle, and REG 135 is not mandatory - any bill of sale that clearly identifies the vehicle and the two parties is acceptable. The DMV’s transfer form, REG 262, even has a built-in bill-of-sale section that can be used instead.

What a bill of sale does is record the terms of a sale - who sold what to whom, for how much, and when. This guide covers what the form captures, the specific situations where the DMV needs one, and why it is a supporting document that never stands in for the signed title.

What a California bill of sale records

A California bill of sale - whether on REG 135 or your own document - generally captures:

• The vehicle identification number (VIN) and the year, make, and model
• The license plate number (and the engine number for a motorcycle)
• Both parties’ names and addresses - seller and buyer
• The sale price, or the gift value if the vehicle is a gift
• The date of sale
• An odometer disclosure - the mileage reading at the time of sale
• The seller’s signature, made under penalty of perjury

REG 135 lays out each of these fields; a homemade bill of sale is acceptable to the DMV as long as it contains the same identifying information.

RVs, trailers, boats and motorcycles

There is no separate RV bill of sale, no trailer bill of sale and no boat bill of sale in California. There is one form, and it is the one above.

REG 135’s own heading reads “Bill of Sale - Vehicle / Vessel Description”. It names no body type at all: not car, not truck, not RV, not trailer. The fields are the identification number, year, model, make, licence plate or CF number, and a motorcycle engine number - which is the only type-specific box on the form. Nothing on it excludes a motorhome, a fifth-wheel, a travel trailer, a camper or a utility trailer, and nothing asks you to use a different document for one.

So if you are selling a motorhome, travel trailer, camper or utility trailer privately, the honest answer is the dull one: it works exactly as it does for a car. Same form, same fields, same signature under penalty of perjury, and the same fact that California does not require a bill of sale at all. If your trailer is small enough to have no separate plate, record the identification number and describe it - the DMV’s test is whether the document clearly identifies what was sold.

What is different for these vehicles sits elsewhere in the transfer, not on the bill of sale:

• a boat or vessel carries a CF number rather than a licence plate, which is why the form’s plate box reads “License Plate/CF #”
• a trailer may be on Permanent Trailer Identification rather than annual registration - though trailer coaches and park trailers with living quarters are excluded from PTI
• an RV registers as a vehicle, and its smog treatment depends on whether it is petrol or diesel - see registration by vehicle type
• driving the larger ones is its own question: a housecar over 40 feet, or a heavy trailer, may need a non-commercial Class A or B licence

When the DMV needs a bill of sale

Most straightforward sales don’t require a separate bill of sale at all - the signed title and a REG 262 carry the transfer. The DMV specifically needs a bill of sale to establish chain of ownership in a few situations:

• The seller is not the registered owner shown on the title. A bill of sale is accepted in lieu of the registered owner’s release signature - the DMV prints “B/S” on the release-of-ownership line to show a bill of sale stands in for that signature.
• Multiple transfers. When a vehicle changed hands more than once without being titled in between, a bill of sale can stand in lieu of an in-between buyer’s signature, documenting each link in the ownership chain.
• A lost or missing title, where the bill of sale supports the paperwork used to replace the title and complete the transfer.

In each case the bill of sale is evidence of how ownership moved - not a replacement for the title itself.

A bill of sale is not a title

A bill of sale is a supporting document - it records a transaction. It is not proof of ownership, and it never replaces the signed, endorsed California Certificate of Title. A buyer holding only a bill of sale, with no endorsed title, cannot obtain a new title from the DMV on that alone. The title is what transfers ownership; the bill of sale supports it.

The connected transfer steps

A bill of sale sits inside the larger transfer process. The connected steps, each with its own rule:

• Register within 10 days. The buyer applies to register the vehicle and transfer the title within 10 days of the sale (Vehicle Code §5902); a late transfer adds penalties.
• Title transfer fee: $15. The DMV title transfer fee is $15, separate from any tax.
• Release of Liability within 5 days. The seller files a Notice of Transfer and Release of Liability (REG 138) within 5 days; filing it ends the seller’s liability for the vehicle after the sale.
• Use tax, not sales tax. A private-party sale owes use tax, collected by the DMV at the buyer’s local rate on the actual price paid. The CDTFA can audit an under-reported value, and declaring a real sale as a gift is a statement made under penalty of perjury.
• Smog certificate. The seller generally provides a valid smog certification within 90 days of the sale, with exemptions for transfers between family members and for newer vehicles.
• Gifts and family transfers. A gift or qualifying family transfer is generally exempt from use tax; the exemption is claimed on a REG 256 (Statement of Facts).