Verifying the HIN / CIN

What the number is

Boats built to European rules carry a craft identification number, CIN, under ISO 10087. It has 14 characters:

• 2 letters for the country of the builder.
• 3 characters for the builder's code.
• 5 characters for the serial number.
• 1 letter for the month of production (A for January to L for December).
• 1 digit for the year of production.
• 2 digits for the model year.

American boats carry a 12-character HIN under a similar scheme.

Where to find it

The standard puts the number on the starboard side of the transom, near the top. The builder also fixes a second copy in a hidden place inside the hull, which helps to identify the boat if the first is removed. Ask the builder, or a surveyor who knows the model, where it is on this boat.

What to check

1. The number on the transom matches the registration, the bill of sale and the VAT papers. See Proving and verifying VAT status: which documents count, and checking before you offer.
2. The country and builder codes match the boat. A French-built Jeanneau begins with FR and the builder's own code.
3. The month and year fit what the seller says about the age.
4. The characters are cut or stamped cleanly, with no signs of grinding, filling or repainting.
5. The hidden number, if you can reach it, matches the transom.

Why it matters

Stolen boats and boats with altered histories change their numbers. A mismatch can mean a clerical error in the papers. It can also mean a stolen boat, or one with unpaid VAT or a lien. Without a clean match, no registry will accept the sale.

Older and one-off boats

Boats built before the standard, and custom boats, may have a builder's plate or a number in another format. Ask the builder or a surveyor to confirm that the format is right for the model.

Related guides

• Due diligence before you pay a deposit
• Checking ownership
• CE marking and the Recreational Craft Directive: design categories A to D