The Letter ID on a Colorado car title isn’t on the title at all. It’s a verification code printed on the Title Complete Notice, a separate letter your county motor vehicle office mails you once your title has been processed. You need it, paired with your title number, to register your vehicle online or complete other digital transactions through the Colorado DMV.
Where the Letter ID Actually Appears
When Colorado finishes processing your title, your county motor vehicle office sends a Title Complete Notice confirming the title is ready. The Letter ID is a code on that notice. Colorado’s online registration system asks for the title number and the Letter ID together to verify your identity and pull up your record, so the state uses it as a security check rather than a permanent vehicle identifier.
This is why people flip the Certificate of Title over and over looking for a field labeled “Letter ID” and come up empty. The title document itself carries the title number (a nine-digit code in the upper right corner) and the VIN. The Letter ID lives only on the mailed notice.
If You Never Got the Notice or Threw It Out
Contact your county motor vehicle office. County staff can look up your Letter ID using your name and vehicle information. Boulder County, for instance, tells residents to call the office for the Letter ID if the notice hasn’t arrived and they want to register online, and most Colorado counties offer the same help by phone or in person.
If the notice simply hasn’t shown up yet, give it a little time before assuming it’s lost. Processing and mailing happen after the title work is complete at the county level, so the notice follows the title, not the application.
When You Need the Letter ID vs. Other Codes
Different transactions call for different identifiers, and it’s easy to grab the wrong one. The Letter ID has a narrow job: online registration and similar digital transactions where the DMV system needs a second piece of information to confirm you’re the owner. For almost everything else, you’ll use the title number or the VIN instead.
Title Number
The nine-digit title number in the upper right corner of the Certificate of Title identifies that specific title document, not the vehicle. A duplicate or replacement title gets a new title number. Colorado uses it to track title issuance, ownership transfers, and liens, and you’ll need it for online registration, duplicate title applications, and most DMV transactions.
VIN
The VIN is the 17-character code printed on the top portion of the title near the vehicle description. Unlike the title number, it stays with the vehicle for its entire life no matter how many times ownership changes. It’s what buyers, insurers, and law enforcement use to pull accident records, ownership history, and odometer readings. A VIN verification is required when titling a vehicle that came from out of state.
Which One Each Transaction Needs
For online vehicle registration through the Colorado DMV, you typically need the title number plus the Letter ID from the Title Complete Notice. When selling your vehicle, the buyer needs the VIN and the properly signed title with its title number. The Letter ID doesn’t come up in a private sale.
If you’re buying a vehicle, you have 60 days after the sale to register it or submit the Certificate of Title with a title application to your county motor vehicle office. Missing that deadline carries a penalty of $15 to $100.
A Few Things the Letter ID Isn’t
The Letter ID is tied to a specific notice, not to you or to the vehicle permanently. If you request a duplicate title later, that process generates its own Title Complete Notice with its own Letter ID when the new title is ready. The old Letter ID isn’t a code you keep on file for years; it’s a one-time credential for completing the registration tied to the title you just received.
It’s also not a substitute for the title number or the VIN. If an online form or a DMV representative asks specifically for the title number or the VIN, the Letter ID won’t work in its place, and vice versa.