California trailer — quick answer
In California, a trailer bill of sale is not required and notarization of the title transfer is not required. The state form used for titled vehicles is REG 135. Titling and registration are handled by the California DMV.
Is a trailer bill of sale required in California?
Not required. A bill of sale is optional. The DMV's REG 135 can stand in for the owner's release-of-ownership signature on the title.
Seller signs the title over to the buyer; the buyer submits the title (or REG 135) and applies for transfer within 10 days.
Does a California trailer bill of sale need to be notarized?
Not required. California's registration manual states a bill of sale is not required to be notarized or witnessed.
What to include on a California trailer bill of sale
- Buyer and seller names and addresses
- Year, make, and trailer type
- VIN or serial number
- Length, number of axles, and empty weight
- Price, date, and signatures
How to transfer a trailer in California
- 1Complete the bill of sale and title assignment.
Record the buyer, seller, price, and date. Both parties sign and date.
- 2Hand over the signed title.
Seller signs the title over to the buyer; the buyer submits the title (or REG 135) and applies for transfer within 10 days.
- 3File a notice of sale / release of liability.
The seller files Notice of Transfer and Release of Liability (file within 5 days) to remove liability.
- 4Register with the California DMV.
The buyer titles and registers the trailer, bringing Bill of Sale. Confirm current fees on the official page.
Official sources
Requirements change and can vary by county. Confirm with the California DMV before you sign. Not legal advice.
California Trailer Bill of Sale — FAQ
Is a trailer bill of sale required in California?
A bill of sale is not required in California. A bill of sale is optional. The DMV's REG 135 can stand in for the owner's release-of-ownership signature on the title.
Does a California trailer bill of sale need to be notarized?
No. California's registration manual states a bill of sale is not required to be notarized or witnessed.
Do I need to title a trailer?
It depends on the trailer’s weight and your state. Heavier trailers usually require a title and registration; many small utility trailers only need registration. Check your state page.
What if my trailer has no VIN?
Homemade or older trailers may need a state inspection to be assigned a VIN before they can be titled. The bill of sale still documents the sale in the meantime.
Is a bill of sale proof of ownership?
Generally no. For titled property like a car or boat, the title is what proves ownership. A bill of sale proves that a sale happened and records the price, date, and terms — it supports the title transfer but does not replace it. For untitled property (furniture, equipment, electronics), the signed bill of sale is usually the main proof of ownership.