Assigned number format
Missouri assigns numbers in the pattern MO 1234 AB, using the MO prefix. Missouri expressly specifies TWO-INCH group spacing.
State Requirement Summary
Missouri Boat Registration Number Requirements
Boats registered in Missouri display an MO-prefixed number such as MO 1234 AB. Missouri calls for characters 3 inches high in block characters of good proportion, reading left to right, contrasting / legible, positioned each side of the bow / forward half. Our lettering is designed to meet the displayed Missouri 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
MO 1234 AB
- Minimum character height
- 3 inches
- Lettering style
- Block characters of good proportion
- Contrast
- Contrasting / legible
- Spacing / separator
- 2-inch spaces between the prefix/suffix and the numerals; a hyphen may appear within the space
- Reading direction
- Left to right
- Number location
- Each side of the bow / forward half
- Validation decal
- Follow the current Missouri-issued placement instructions
- State agency
- Missouri Department of Revenue
What we sell vs. what the state issues: RegistrationDecals.com supplies the registration-number lettering, designed to meet the displayed Missouri size and formatting requirements. Missouri Department of Revenue 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 MO numbers
Starts with the Missouri format (MO 1234 AB). 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 Missouri requirements. Missouri Department of Revenue issues the validation decal.
Missouri placement diagram
Both sides of the hull carry the number. The grey square marks where the state-issued validation decal goes — follow the current missouri-issued placement instructions.
- Height: 3 inches, block characters of good proportion
- Spacing: 2-inch spaces between the prefix/suffix and the numerals; a hyphen may appear within the space
- Location: Each side of the bow / forward half
- Validation decal: Follow the current Missouri-issued placement instructions
Diagram is illustrative. Confirm exact positioning against the instructions issued with your Missouri registration.
Official source
Missouri Department of Revenue — Primary state agency source. Last verified August 22, 2026 (source check 2026-08-22).
Missouri Department of Revenue — Titling and registrationRegistration 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.
Missouri rules in detail
Minimum character height
Missouri 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
Block characters of good proportion, reading left to right. Script, italic and decorative treatments are not what this style describes.
Contrast requirement
Contrasting / legible. 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
2-inch spaces between the prefix/suffix and the numerals; a hyphen may appear within the space. Example: MO 1234 AB. Running the groups together with no separation does not match the stated format.
Placement on the hull
Each side of the bow / forward half. No other number displayed on either side of the bow.
Validation decal placement
Follow the current Missouri-issued placement instructions. The validation or expiration decal is issued by Missouri Department of Revenue — RegistrationDecals.com supplies the registration-number lettering only.
Common mistakes
- Ordering the number without the MO 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 block characters of good proportion.
- Losing the required separation between the groups — 2-inch spaces between the prefix/suffix and the numerals; a hyphen may appear within the space.
- Placing the state validation decal somewhere other than the position Missouri describes: follow the current Missouri-issued placement instructions.
Frequently asked questions
What does a Missouri boat registration number look like?
Missouri numbers follow the pattern MO 1234 AB, using the MO prefix, a numeral group, and suffix letters.
How tall do Missouri boat registration numbers have to be?
3 inches, measured on the character itself, in block characters of good proportion.
What lettering style does Missouri require?
Block characters of good proportion, reading left to right, and contrasting / legible.
How much space goes between the letters and numbers in Missouri?
2-inch spaces between the prefix/suffix and the numerals; a hyphen may appear within the space. Example: MO 1234 AB.
Where do the numbers go on the boat in Missouri?
Each side of the bow / forward half. No other number displayed on either side of the bow.
Where does the Missouri validation decal go?
Follow the current Missouri-issued placement instructions. The decal itself is issued by Missouri Department of Revenue; we supply the registration-number lettering.
Who regulates boat registration numbers in Missouri?
Missouri Department of Revenue. Confirm the current instructions issued with your registration before applying anything to your hull. Last regulatory review: August 22, 2026.
Can I order Missouri boat registration numbers online?
Yes. Enter your assigned MO 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 Missouri registration numbers?
You need the number displayed on both sides of the vessel — each side of the bow / forward half — so every order ships as a matched port-and-starboard pair.
Related guides
Ready to design your MO numbers?
Our designer starts with plain block characters and proper group spacing, so you can see exactly how MO 1234 AB will read on your hull before you order.
Source: Missouri Department of Revenue · 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.