What you need to register a trailer in California
California requires registration for most trailers, but the process and cost depend on the trailer's weight and how you use it. A utility trailer under 1,500 pounds does not need registration. Trailers 1,500 pounds or heavier must be registered with the California Department of Motor Vehicles (DMV), and the registration fee varies based on the trailer's gross vehicle weight rating (GVWR).
You will need the vehicle's title or a bill of sale, proof of ownership, and identification. If the trailer is new, you may have a manufacturer's statement of origin instead of a title. If you are registering a used trailer you bought from a private party, bring the signed title from the previous owner. The DMV will assign your trailer a license plate, which must be displayed on the back of the trailer.
Registration is valid for two years in California. You can renew by mail, online, or in person at a DMV office. The renewal notice will arrive about 60 days before your registration expires.
Key Takeaways
- Trailers under 1,500 pounds do not require California registration, but heavier trailers must be registered with the DMV.
- Registration fees are based on the trailer's gross vehicle weight rating, not its actual weight, and range depending on size.
- You will need a title, bill of sale, or manufacturer's statement of origin plus proof of ownership to register.
- California trailer registration lasts two years and can be renewed by mail, online, or at a DMV office.
- Your registered trailer receives a license plate that must be displayed on the back of the unit.
Trailers that do not need California registration
Not every trailer requires DMV registration. Utility trailers under 1,500 pounds GVWR are exempt from registration. This includes small equipment trailers, yard trailers, and lightweight cargo carriers commonly used for personal purposes. You do not need a license plate for these trailers, and you do not pay a registration fee.
However, if you tow an unregistered trailer on public roads, you must still follow California traffic laws. The towing vehicle must have valid registration and insurance. If you are unsure whether your trailer meets the 1,500-pound threshold, check the manufacturer's label on the trailer frame or contact the DMV to confirm.
Registration fees and weight-based costs
California calculates trailer registration fees based on the GVWR, which is the maximum weight the trailer can safely carry including its own weight. This is not the same as the trailer's actual weight. The GVWR is printed on a label attached to the trailer frame by the manufacturer.
Fees increase with weight. A trailer with a GVWR of 1,500 to 2,000 pounds costs less than one rated for 5,000 pounds. The DMV website lists the current fee schedule by weight category. Registration is valid for two years, so you will pay this fee every two years when you renew. If you register a trailer partway through the year, you may pay a prorated fee.
How to register a new trailer
For a new trailer you just purchased, bring the manufacturer's statement of origin (MSO) or the bill of sale to a DMV office, along with your identification and proof of residence. If the dealer is handling the paperwork, they will submit the MSO to the DMV on your behalf, and you will receive the registration and plates by mail within a few weeks.
If you are registering the trailer yourself, fill out Form REG 343 (process for Title or Registration) and submit it in person or by mail with the MSO and the registration fee. The DMV will issue a title in your name and send you the license plate. Keep the registration card and proof of registration in your vehicle when towing the trailer.
How to register a used trailer
When you buy a used trailer from a private seller, the previous owner must sign the back of the title and give it to you. Bring the signed title, your identification, and proof of residence to a DMV office. If the title is missing or the seller cannot locate it, you can request a duplicate title from the DMV, but this adds time to the process.
Complete Form REG 343 and pay the registration fee based on the trailer's GVWR. The DMV will issue a new title in your name and assign a license plate. If you buy from a dealer, they typically handle the title transfer and registration paperwork, and you will receive the documents by mail.
Renewing your trailer registration
California sends renewal notices about 60 days before your registration expires. You can renew online through the DMV website if you have your registration card and vehicle identification number (VIN). Online renewal is the fastest option and takes a few minutes.
You can also renew by mail by returning the renewal notice with the fee, or in person at any DMV office. Renewing by mail takes about two weeks. Do not let your registration expire, because towing an unregistered trailer is a violation. If your registration has been expired for more than a few months, you may need to register the trailer again from scratch rather than straightforward renewing.
License plates and display requirements
When you register a trailer in California, the DMV issues a license plate specific to that trailer. The plate must be mounted on the back of the trailer and must be visible and readable from at least 20 feet away. The plate should be kept clean and not obscured by dirt, cargo, or other objects.
If your license plate is lost, stolen, or damaged, you can request a replacement from the DMV. Bring your registration card and identification to a DMV office, or request a duplicate plate by mail. There is a small fee for a replacement plate. Do not use a plate from another vehicle or a homemade plate, as this is illegal.
Frequently Asked Questions
Do I need insurance for my registered trailer?
California does not require separate insurance for a trailer if it is covered under your vehicle's liability policy. However, check with your insurance company to confirm your trailer is included. If you are towing expensive cargo or a high-value trailer, you may want additional coverage.
What if I lose the title to my trailer?
You can request a duplicate title from the DMV by completing Form REG 227 (process for Duplicate or Paperless Title) and paying a small fee. Bring your identification and proof of ownership, such as a registration card or bill of sale. The DMV will mail the duplicate title to you within a few weeks.
Can I register a trailer online?
You can renew an existing trailer registration online through the DMV website. However, you cannot register a new trailer online. New registrations require you to visit a DMV office or submit paperwork by mail with the title or MSO and proof of ownership.
What happens if I tow a trailer without registration?
Towing an unregistered trailer that requires registration is a traffic violation. You may receive a citation and be required to pay a fine. If the trailer is over 1,500 pounds GVWR, it must be registered before you tow it on public roads.
How long does trailer registration take?
If you register in person at a DMV office, you may receive your plates the same day or within a few days. If you register by mail, allow two to four weeks for processing. If a dealer is handling the registration, expect three to four weeks to receive your documents by mail.