Assigned number format
Idaho assigns numbers in the pattern ID 5678 A, using the ID prefix. Idaho also has separate invasive-species sticker requirements that should not be confused with the registration decal.
State Requirement Summary
Idaho Boat Registration Number Requirements
Boats registered in Idaho display an ID-prefixed number such as ID 5678 A. Idaho calls for characters 3 inches high in plain vertical block characters, reading left to right, must contrast with background, positioned each side of the forward half. Our lettering is designed to meet the displayed Idaho size and formatting requirements. The state itself issues the validation/expiration decal — we supply the registration-number lettering.
Boat number requirements
Last regulatory review: August 22, 2026
Assigned number example
ID 5678 A
- Minimum character height
- 3 inches
- Lettering style
- Plain vertical block characters
- Contrast
- Must contrast with background
- Spacing / separator
- Space or hyphen equal to the width of an ordinary character
- Reading direction
- Left to right
- Number location
- Each side of the forward half
- Validation decal
- Follow the Idaho registration decal instructions
- State agency
- Idaho Department of Parks and Recreation
What we sell vs. what the state issues: RegistrationDecals.com supplies the registration-number lettering, designed to meet the displayed Idaho size and formatting requirements. Idaho Department of Parks and Recreation 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.
Design your ID numbers
Starts with the Idaho format (ID 5678 A). Tap the decal and type your own assigned number exactly as it appears on your certificate of number.
Tap the decal to edit
Decal color
We supply the registration-number lettering, sized to the displayed Idaho requirements. Idaho Department of Parks and Recreation issues the validation decal.
Idaho placement diagram
Both sides of the hull carry the number. The grey square marks where the state-issued validation decal goes — follow the idaho registration decal instructions.
- Height: 3 inches, plain vertical block characters
- Spacing: Space or hyphen equal to the width of an ordinary character
- Location: Each side of the forward half
- Validation decal: Follow the Idaho registration decal instructions
Diagram is illustrative. Confirm exact positioning against the instructions issued with your Idaho registration.
Official source
Idaho Department of Parks and Recreation — Primary state agency source. Last verified August 22, 2026 (source check 2026-08-22).
Idaho Department of Parks and Recreation — 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.
Idaho rules in detail
Minimum character height
Idaho specifies characters 3 inches high. Measure the character body itself — if the state excludes borders, outlines or shading, decorative trim does not count toward the minimum.
Required lettering style
Plain vertical block characters, reading left to right. Script, italic and decorative treatments are not what this style describes.
Contrast requirement
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.
Spacing and separator
Space or hyphen equal to the width of an ordinary character. Example: ID 5678 A. Running the groups together with no separation does not match the stated format.
Placement on the hull
Each side of the forward half. Must remain clearly visible.
Validation decal placement
Follow the Idaho registration decal instructions. The validation or expiration decal is issued by Idaho Department of Parks and Recreation — RegistrationDecals.com supplies the registration-number lettering only.
Common mistakes
- Ordering the number without the ID prefix or the suffix letters.
- Characters shorter than the stated minimum (3 inches) so they fit inside a narrow accent stripe.
- Using a script, italic or shadowed style instead of plain vertical block characters.
- Losing the required separation between the groups — space or hyphen equal to the width of an ordinary character.
- Placing the state validation decal somewhere other than the position Idaho describes: follow the Idaho registration decal instructions.
Frequently asked questions
What does a Idaho boat registration number look like?
Idaho numbers follow the pattern ID 5678 A, using the ID prefix, a numeral group, and suffix letters.
How tall do Idaho boat registration numbers have to be?
3 inches, measured on the character itself, in plain vertical block characters.
What lettering style does Idaho require?
Plain vertical block characters, reading left to right, and must contrast with background.
How much space goes between the letters and numbers in Idaho?
Space or hyphen equal to the width of an ordinary character. Example: ID 5678 A.
Where do the numbers go on the boat in Idaho?
Each side of the forward half. Must remain clearly visible.
Where does the Idaho validation decal go?
Follow the Idaho registration decal instructions. The decal itself is issued by Idaho Department of Parks and Recreation; we supply the registration-number lettering.
Who regulates boat registration numbers in Idaho?
Idaho Department of Parks and Recreation. Confirm the current instructions issued with your registration before applying anything to your hull. Last regulatory review: August 22, 2026.
Can I order Idaho boat registration numbers online?
Yes. Enter your assigned ID 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.
Do I need two sets of Idaho registration numbers?
You need the number displayed on both sides of the vessel — each side of the forward half — so every order ships as a matched port-and-starboard pair.
Related guides
Ready to design your ID numbers?
Our designer starts with plain block characters and proper group spacing, so you can see exactly how ID 5678 A will read on your hull before you order.
Source: Idaho Department of Parks and Recreation · Primary state agency source · Primary regulatory material · 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.