What You Need to Register a Trailer in Colorado
Colorado requires you to register any trailer you own, whether you use it regularly or store it most of the year. The Colorado Department of Revenue handles trailer registration, and you'll complete the process through your county clerk's office or online through the state system. Most trailers need a title and registration certificate, though some smaller or older trailers may have different rules.
The basic documents you'll need are proof of ownership (a title or bill of sale), proof of Colorado residency, and identification. If you're registering a used trailer, you'll also need the previous owner's title or a release of lien if there's a loan against it. The county clerk will verify these documents and issue your registration and license plate.
Key Takeaways
- You must register your trailer through your county clerk's office, and the process requires a title or bill of sale plus proof of Colorado residency.
- Registration fees vary by trailer weight and type, and you'll pay them once per year when you renew.
- Trailers under 1,500 pounds may have different registration requirements, so check with your county clerk about your specific trailer.
- You can register online through the Colorado Department of Revenue website if you have a title and your trailer's VIN, which speeds up the process.
- Once registered, you'll receive a license plate and registration certificate that must be displayed on your trailer.
Documents You'll Bring to the County Clerk
Start by gathering your proof of ownership. If you bought the trailer from a dealer or private owner, you should have a title issued by Colorado or another state. If the title is from out of state, bring it anyway — the county clerk will process it and issue a Colorado title. If you don't have a title (common with very old trailers or homemade ones), bring a bill of sale signed by the previous owner with the purchase date and price.
Next, bring proof that you live in Colorado. A utility bill, lease agreement, or mortgage statement dated within the last 60 days works. You'll also need a valid ID — a driver's license, passport, or state ID card. If someone else owns the trailer but you're registering it, bring a notarized power of attorney or a letter from the owner authorizing you to register it on their behalf.
If the trailer has a lien (meaning a bank or lender holds a claim against it), the title will show that. You'll need written permission from the lien holder to register it, or proof that the lien has been released. The county clerk can help you understand what paperwork the lien holder needs to provide.
Registration Fees and What They Cover
Colorado charges registration fees based on your trailer's dry weight — the weight without cargo or fluids. Lighter trailers cost less to register than heavier ones. The state also charges a one-time title fee when you first register a trailer in Colorado, which is separate from the annual registration fee. Both fees are set by the state, so they're the same no matter which county you register in.
Your registration is valid for one year from the month you register. When it expires, you'll renew it through your county clerk or online. Renewal is simpler than the first registration — you won't need to bring documents again unless something has changed, like the trailer's ownership or address.
If your trailer is financed, the lender may require you to carry liability insurance. Check your loan paperwork to see if insurance is mandatory. Even if it's not required, liability coverage protects you if your trailer causes damage to someone else's property.
Registering Online vs. In Person
Colorado allows you to register some trailers online through the Department of Revenue website if you have a title in hand and know your trailer's VIN (vehicle identification number). The VIN is stamped on the trailer frame, usually on the tongue or near the axle. Online registration takes about 10 minutes and you can pay the fee with a credit card.
If you register online, you'll still need to visit your county clerk to pick up your license plate and registration certificate. The state will email you a confirmation, and you can bring that to the clerk's office. Some county clerks also allow you to order the plate online and have it mailed to you, though this takes longer.
Register in person at your county clerk's office if you don't have a title, if the title is from another state, or if you're unsure about your trailer's status. The clerk can answer questions about whether your specific trailer needs registration and what documents you're missing. Walk-in hours vary by county, so call ahead or check the county website.
Trailers That May Not Need Full Registration
Colorado has different rules for trailers under 1,500 pounds. Some very light trailers — like small utility trailers or boat trailers — may only need a registration sticker rather than a full title and registration certificate. Check with your county clerk about your trailer's weight and type, because the rules depend on how you plan to use it.
Trailers that are registered to a business address may have different renewal dates or fee structures than personal trailers. If you're registering a trailer for a business, ask the county clerk whether you need a business license number or tax ID on the registration.
Homemade or custom trailers sometimes need an inspection before registration. If your trailer was built rather than manufactured, the county clerk will tell you whether an inspection is required and which inspection stations are authorized to do it.
What Happens After Registration
Once the county clerk processes your registration, you'll receive a metal license plate and a registration certificate. The plate must be mounted on the back of your trailer where it's visible. The certificate should be kept in a safe place — you don't need to carry it with you, but you should have it if you're asked to prove registration.
Your registration is now active and valid for one year. If you sell the trailer, notify the county clerk so the registration transfers to the new owner. If you move out of Colorado, you'll need to cancel your registration and register the trailer in your new state.
If your registration expires and you haven't renewed it, you cannot legally tow the trailer on Colorado roads. Renew before the expiration date shown on your certificate. Most county clerks send renewal notices by mail about 30 days before expiration, but don't rely on receiving one — mark your calendar and renew on time.
Frequently Asked Questions
Do I need a title to register a trailer in Colorado?
A title is the standard proof of ownership, but if you don't have one, a bill of sale signed by the previous owner works. Very old trailers or homemade ones sometimes can't get a title. Ask your county clerk whether your trailer can be titled — if not, they'll explain what documents you need instead.
Can I register a trailer I just bought from out of state?
Yes. Bring the out-of-state title to your county clerk, along with proof of Colorado residency and your ID. The clerk will process the out-of-state title and issue a Colorado title and registration. You'll pay Colorado's registration fee based on the trailer's weight.
What if I don't know my trailer's VIN?
The VIN is stamped on the trailer frame, usually on the tongue or near the axle. Look for a metal plate or stamped numbers. If you can't find it, bring the trailer to your county clerk's office and they can help you locate it or note its absence on the registration.
How much does trailer registration cost in Colorado?
Fees vary by trailer weight and are set by the state. Lighter trailers cost less than heavier ones. Contact your county clerk or check the Colorado Department of Revenue website for the exact fee for your trailer's weight class.
Can I renew my registration online?
Yes, you can renew online through the Colorado Department of Revenue website if your registration is current and nothing has changed. You'll still need to pick up your new license plate at the county clerk's office, though some counties mail plates to you.