State Requirement Summary
Boats registered in Colorado display a CL-prefixed number such as CL 3717 ZW. Colorado uses the CL prefix rather than CO — that difference alone is a common ordering mistake. Colorado calls for characters 3 inches, excluding border or trim high in block characters of good proportion, reading left to right, must contrast with background, positioned each side of the forward half / bow. Our lettering is designed to meet the displayed Colorado size and formatting requirements. The state itself issues the validation/expiration decal — we supply the registration-number lettering.
Last regulatory review: August 22, 2026
Assigned number example
CL 3717 ZW
Colorado uses the CL prefix — not CO.
What we sell vs. what the state issues: RegistrationDecals.com supplies the registration-number lettering, designed to meet the displayed Colorado size and formatting requirements. Colorado Parks and Wildlife issues the official validation/expiration decal — and any separate stickers such as aquatic-invasive-species, mussel-awareness, carbon-monoxide or lake-protection stickers, which are not interchangeable with each other.
Starts with the Colorado format (CL 3717 ZW). Tap the decal and type your own assigned number exactly as it appears on your certificate of number.
Tap the decal to edit
We supply the registration-number lettering, sized to the displayed Colorado requirements. Colorado Parks and Wildlife issues the validation decal.
Both sides of the hull carry the number. The grey square marks where the state-issued validation decal goes — to the left of the registration number on both sides.
Diagram is illustrative. Confirm exact positioning against the instructions issued with your Colorado registration.
Colorado Parks and Wildlife — Primary state agency source. Last verified August 22, 2026 (source check 2026-08-22).
Colorado Parks and Wildlife — BoatingRegistration requirements can change. RegistrationDecals.com summarizes publicly available boating-registration requirements to help boat owners select and display registration numbers. Always compare your registration and decals with the current instructions issued by your state boating or registration agency before applying them to your vessel.
Colorado assigns numbers in the pattern CL 3717 ZW, using the CL prefix. Note that the vessel prefix (CL) is not the postal abbreviation (CO). Decal-before-number placement is an important Colorado exception, and the vessel prefix is CL, not CO.
Colorado specifies characters 3 inches, excluding border or trim high. Measure the character body itself — if the state excludes borders, outlines or shading, decorative trim does not count toward the minimum.
Block characters of good proportion, reading left to right. Script, italic and decorative treatments are not what this style describes.
Must contrast with background. In practice that means dark characters on a light hull and light characters on a dark hull, checked in daylight from the side of the vessel.
Space or hyphen between letter and numeral groups. Example: CL 3717 ZW. Running the groups together with no separation does not match the stated format.
Each side of the forward half / bow. Must remain clearly visible and legible.
To the LEFT of the registration number on both sides. The validation or expiration decal is issued by Colorado Parks and Wildlife — RegistrationDecals.com supplies the registration-number lettering only.
Colorado numbers follow the pattern CL 3717 ZW, using the CL prefix, a numeral group, and suffix letters.
3 inches, excluding border or trim, measured on the character itself, in block characters of good proportion.
Block characters of good proportion, reading left to right, and must contrast with background.
Space or hyphen between letter and numeral groups. Example: CL 3717 ZW.
Each side of the forward half / bow. Must remain clearly visible and legible.
To the LEFT of the registration number on both sides. The decal itself is issued by Colorado Parks and Wildlife; we supply the registration-number lettering.
Colorado Parks and Wildlife. Confirm the current instructions issued with your registration before applying anything to your hull. Last regulatory review: August 22, 2026.
Yes. Enter your assigned CL number in the designer on this page, pick a color that contrasts with your hull, and we cut a matched port-and-starboard pair and ship it to the 48 contiguous states.
CL. Colorado-registered vessels display the CL prefix — ordering CO produces the wrong number.
Our designer starts with plain block characters and proper group spacing, so you can see exactly how CL 3717 ZW will read on your hull before you order.
Source: Colorado Parks and Wildlife · Primary state agency source · Primary · Source last checked 2026-08-22.
Registration requirements can change. RegistrationDecals.com summarizes publicly available boating-registration requirements to help boat owners select and display registration numbers. Always compare your registration and decals with the current instructions issued by your state boating or registration agency before applying them to your vessel.
