State Compliance Guide

Indiana Boat Registration Decal Requirements

Every motorized vessel operated on Indiana public waters must display its IN-prefixed registration number on both sides of the forward half of the hull, along with the current state validation decal. Indiana enforces specific rules on letter height, font style, color contrast, separator spacing, and exactly where the validation decal sits relative to the number. The summary below covers the requirements most commonly missed during inspections.

Quick reference

Letter height
3″ minimum
Font
Solid block font; no shadows, outlines, or italics permitted
Contrast
Required — must contrast with hull
Separator
Space or hyphen
Decal placement
Positioned directly in line with the numbers

Detailed rules

Letter height and font

Letters and numbers must be at least 3 inches tall, in solid block font; no shadows, outlines, or italics permitted. Script, italic, shadowed, and outlined fonts are not acceptable. Stroke width should be heavy enough that the sequence reads cleanly from at least 100 feet away in daylight.

Color and contrast

The number must be a color that sharply contrasts with the hull. Light hulls (white, cream, light gray) require dark letters; dark hulls require light letters. Reflective vinyl is permitted as long as the underlying contrast holds during the day.

Separator between prefix and digits

Space or hyphen must separate the IN prefix, the digit group, and the suffix letters. Example: IN 1234 AB or IN-1234-AB. Running the characters together is a violation.

Validation decal placement

Positioned directly in line with the numbers. The decal must be on both sides of the forward half of the hull and clearly visible from the side of the vessel.

Position on the hull

Numbers go on both sides of the forward half of the vessel, above the waterline, in an unobstructed location, reading left to right. Anything that covers or partially obscures the sequence — rub rails, fenders, accessories — can cause an inspection failure.

Common compliance mistakes

  • Using script, italic, or outlined fonts that look great on a boat name but fail Indiana inspection.
  • Placing the validation decal in the wrong position relative to the number — see the rule above for exact Indiana placement.
  • Letters under 3" tall because they had to fit a narrow accent stripe.
  • Low-contrast color combos like dark navy numbers on a black hull stripe.

Frequently asked questions

How tall do Indiana boat registration numbers have to be?

At least 3 inches tall, measured from the top to the bottom of the character, in solid block font; no shadows, outlines, or italics permitted.

Can I use a stylized or script font on my Indiana boat?

No. Indiana requires plain, vertical block characters. Script, italic, shadowed, and outlined fonts are not compliant.

Where does the validation decal go on a Indiana-registered boat?

Positioned directly in line with the numbers, on both sides of the forward half of the hull.

Do I need a hyphen between IN and the numbers?

Space or hyphen. IN 1234 AB and IN-1234-AB are both acceptable; IN1234AB is not.

Strict visual styling mandates prohibit stylized, slanted, or multi-colored fonts — anything I should know?

Strict visual styling mandates prohibit stylized, slanted, or multi-colored fonts.

Ready to design your IN decals?

Our online designer enforces the 3-inch height, plain block font, and contrast rules automatically — so what you preview is what passes inspection.

Source: Reference · Always verify current requirements with your state boating authority before relying on this guide for compliance.