Michigan Boat Registration Numbers: Size, Spacing and Decal
Michigan boats carry an MC number on each side of the forward half and a validation decal 3 inches after the last letter. Here is the rule in plain words.
Michigan boats carry an MC registration number on each side of the forward half and a validation decal beside it. The rule sits in the Michigan Department of Natural Resources rules on numbering of vessels and motorboats. This guide summarizes it in plain words and is not legal advice. The rule text is updated, so check the current version on the state's site before you apply anything.
The number
- It goes on each side of the forward half of the boat, as high above the waterline as practical.
- The characters are plain vertical block characters at least 3 inches tall.
- The color contrasts with the background.
- The letter group and the number group are separated by a space or hyphen. Michigan's rule gives the width as that of the letter M. The example in the rule is MC-3717-ZW.
- Nothing else may be displayed on the bow: no other numbers on either side of the bow.
The validation decal
- It is about 3 inches square and permanently attached to each side of the forward half.
- It goes 3 inches beyond the last character of the number and on the same strake or level as the number.
- The decal's color shows the expiration year. Registrations expire on March 31 in the third year of issue.
Which boats need a number
Michigan numbers motorized boats and larger non-motorized boats, with exemptions for small paddle craft. The thresholds in the rule text we saw were not consistent between sources, so read the Department of Natural Resources page for your boat before you decide.
Common mistakes
- Putting other numbers or lettering on the bow, such as a model number or a name close to the registration number.
- Spacing the groups with a gap that is much narrower than a letter M.
- Placing the decal above or below the number instead of at the same level.
- Placing the number too low on the hull.
- Leaving an old decal on.
Ordering the number
Sources
Frequently asked questions
How tall do Michigan boat numbers have to be?
At least 3 inches, in plain vertical block characters, according to the Michigan rule on numbering of vessels and motorboats. That matches the federal floor (33 CFR 173.27).
Where does the Michigan decal go?
On each side of the forward half, 3 inches beyond the last character and at the same level as the number. It is about 3 inches square.
Can I put my boat name on the bow?
The rule says no other numbers may be displayed on either side of the bow, and asks that nothing else be displayed there. Put the name elsewhere, such as the stern or higher on the side, and confirm with the agency.
How high on the hull should the number go?
As high above the waterline as practical, on the forward half. Check the rule for what counts as practical on your boat.
Do letters and numbers need a space between them?
Yes. Use a space or hyphen as wide as the letter M, as in MC-3717-ZW.
How long does a registration last?
The rule text says registrations expire March 31 in the third year after issue. Check the current term on the state's page.
Can I order just one decal?
Yes, but most boats need two, one for each side. The quantity on our page starts at 2.
Our boat registration number decals are made from the number you type, in block letters from 3 to 5 inches tall. The page shows the width, so you can allow for the 3 inch gap and the decal. The validation decal comes from the state. For the federal summary see the boat registration number rules.
Checked 2026-10-13. Rules change, so confirm with the state.
See it on a truck door first
Type your lines, pick the size and colors, and watch your decal on the door. Questions? Email info@workdecals.com.