Canadian · Validation
Hull identification number validator.
Check that a boat's 12-character HIN is laid out the way US Coast Guard rules require, and see what each part says. Format only; a HIN has no checksum.
The layout: 3-character manufacturer code, 5-character serial number (no I, O or Q), 1 month letter A to L, 1 digit for the year of manufacture or certification, and 2 digits for the model year. Example: ABC2AB41G091 is July 1990, 1991 model year.
Inputs
Result
Enter a hull identification number and press Check.
How a hull identification number is formed
US recreational boats carry a 12-character hull identification number (HIN), stamped on the hull. 33 CFR 181.25 sets its layout, with no spaces, hyphens or slashes.
- Characters 1-3: the manufacturer identification code (MIC), assigned by the Coast Guard. The third character can be a digit.
- Characters 4-8: the serial number chosen by the builder, letters and digits except I, O and Q.
- Character 9: the month of certification or manufacture as a letter: A = January through L = December.
- Character 10: the last digit of that year.
- Characters 11-12: the last two digits of the model year. It does not have to match the year in character 10.
Examples from the Coast Guard: ABC2AB41G091 (July 1990, 1991 model year) and ABC00001H790 (August 1987, 1990 model year; legal even though the model year is later).
Older boats: between 1972 and 1984 the date could be written as four digits, month then year (December 1972 as ABC000011272), or in a second older style. The Coast Guard says both are no longer legal for boats built on or after August 1984, so this tool reports such a number as not a current-format HIN, and reads only the four-digit month-and-year style.
Sources: 33 CFR 181.25 and US Coast Guard Boating Safety Circular 70, “HIN 101”, which agree on every field.
Format only — not a registration or theft check
This tool checks how the number is written, entirely in your browser. A HIN has no checksum, so a correctly laid-out number can still be one that was never issued. It cannot confirm that the number belongs to a real boat, that the manufacturer code is assigned, or that the boat is registered, titled or not stolen. Nothing you type is transmitted, stored, or logged.