Boats With No HIN: State-Assigned Hull Numbers for Homebuilt, Pre-1972 and Damaged-HIN Boats

You probably do if:

• You built the boat, or finished a kit.
• The boat was built after October 1972 and has no HIN, or it's unreadable.
• Your state's records show a HIN that's incomplete or not in the standard format. New York, for example, may ask for a pencil tracing, photo or officer's statement, and if the number is incomplete or nonstandard, asks you to apply for a new one.
• The registration doesn't show the model year (another New York trigger).
• Your state requires a HIN on older boats too. Florida law requires a titled or registered vessel completed before November 1972 to display a HIN, and the state assigns one if the builder didn't.

A missing HIN is sometimes just hidden.

• Clean and check the starboard side of the transom near the top, the usual spot. On boats without a transom, look on the starboard side near the stern.
• Federal rules call for a second, hidden HIN inside the boat or under a fitting or piece of hardware. Look under hatches, behind panels and under the console.
• On older boats, look for a builder's plate, serial number or capacity plate with the maker's name.
• Check old registrations, titles, bills of sale and insurance papers for a number.
• California notes it will correct its records if documentation shows an existing HIN.

If you find a valid number, you may only need to update the state's records rather than get a new HIN.

Search your state boating agency's site for "hull identification number," "homemade boat" or "assigned HIN." Patterns you'll see:

• New York: apply to State Parks on form OPS-420 before registering a homemade boat or any post-1972 boat without a HIN.
• Texas: homemade boats need an affidavit of origin and proof of materials, and a game warden inspects the boat and issues the HIN.
• California: at the owner's request, DMV assigns a HIN at no fee to a vessel that lacks one, with the ownership certificate and a statement of facts form saying the boat has no HIN and naming the builder if known.
• Michigan: the secretary of state assigns a HIN on an application that includes proof of ownership.
• Florida: the state assigns HINs for homemade vessels and boats that lack a builder's number.
• Massachusetts: a homemade boat, or one built before 1972 without a 12-character HIN, must be inspected by the Environmental Police before registration (you request it online or by phone). Bring ID, the title or the seller's registration, and for a homemade boat the receipts for your materials. The inspection certificate goes to the registration office, which assigns the HIN, and you have to prove the number is on the boat before you get the registration card and decal.

States want to be sure the boat isn't stolen. Depending on the state, accepted proof can include:

• A title or registration from another state
• A bill of sale for the boat, or for the materials it was built from (Michigan lists both)
• Past or current registration cards
• A sworn statement of ownership, or a court order

For a used boat with no HIN, get a detailed bill of sale with the seller's full contact information, and a copy of their ID if they agree.

• Keep every receipt for the hull materials, plywood, epoxy, fiberglass, kit, motor and trailer. New York says receipts and proof of ownership for major components and materials must be available at the inspection; Texas asks for dealer invoices.
• Take dated photos during the build.
• Write down the length, beam, hull material, propulsion and fuel; forms ask for these.
• If you bought a kit, keep the kit maker's invoice and any paperwork it came with.

Follow your state's form exactly. As an example, New York's OPS-420 asks for owner details, the boat's length, width, hull color and material, propulsion, fuel, and where the boat is kept, plus two photos (a view of the stern and a side view showing any registration number). New York says to mail only the form and photos, without money or ownership proofs, and your signature authorizes the inspection.

Most states inspect the boat before assigning a number.

• In New York, State Parks reviews the application and sends it to the local marine law enforcement agency (usually the county sheriff), which calls to schedule an inspection, generally where the boat is kept.
• In Texas, a game warden inspects homemade boats.
• Have the boat clean, accessible and uncovered, with your receipts, bills of sale and ID ready. Point out any old numbers or plates you found.

A state-assigned HIN still has 12 characters, but the first part identifies the state instead of a builder. California, for example, uses "CFZ" followed by part of the boat's CF registration number and characters for the month and year of manufacture (or the year fees were paid if the build date is unknown). Other states use their own prefix. Copy the number exactly from the paperwork, and double-check every character before you mark the hull.

Knowing the federal layout (33 CFR 181.25) helps you catch copying mistakes:

• Characters 1 to 3: the maker or importer code (or the state's code on an assigned HIN).
• Characters 4 to 8: the serial number. The letters I, O and Q are never used here, so what looks like an "O" is a zero and what looks like an "I" is a one.
• Character 9: a letter for the month (A for January through L for December).
• Character 10: the last digit of the year of manufacture or certification.
• Characters 11 and 12: the model year, such as "26" for 2026.
• No dashes, slashes or spaces between characters on the hull.

Your state's assigned number may follow its own rules for the date characters, as California's does, so follow the paperwork it gives you.

Follow your state's instructions; if they're silent, these federal and state rules are a good guide:

• Permanent and tamper-evident: 33 CFR 181.29 says the number must be carved, burned, stamped, embossed, molded, bonded or otherwise permanently fixed so that changing or removing it would be obvious. A separate plate must be fastened so that removing it would scar the hull, and the number must not go on removable parts.
• Location: Florida and Michigan both require the outboard side of the transom, or, with no transom, the outermost starboard side at the end that carries the rudder or steering, above the waterline.
• Size: both states require characters at least a quarter inch tall; Florida also requires at least 12 characters.
• Second, hidden copy: California asks for the HIN in two places: one visible, and one in an unexposed spot inside the boat or under a fitting.
• Michigan lets the owner, or someone at the owner's request, fix the number, and lists methods such as non-removable riveting or welding. Ask your state which methods it accepts on fiberglass, wood or aluminum.

Some states verify that the number has been fixed before they register the boat; 33 CFR 174.16 requires the state to check.

New York, for example, says that once the boat passes inspection and has a HIN, you can apply for registration and title at the DMV, bringing your receipts and proof of ownership again. Then display the registration numbers and decals; see our registration numbers guide.

This is where you need to be careful.

• Buying: a ground-off, painted-over, restamped or re-plated HIN is the biggest red flag in a used boat. Walk away and consider telling local law enforcement. Texas makes it illegal to possess, sell or buy a vessel or outboard with an altered, defaced or removed number, and Florida makes it a felony and allows the boat to be seized.
• Already own it legitimately: states have a process. Texas, for example, requires a sworn statement describing the boat or motor, proof of legal ownership and the reason the number was damaged, plus a fee and a game warden's inspection certificate. Contact your state agency before doing anything to the hull.
• Never buy or use a HIN plate meant for another boat; Florida law bans counterfeit and transferred HIN plates.

Rebuilding a transom can destroy the HIN. Florida allows removal only to make necessary repairs, and requires the number to be put back right after the work. Before you start: photograph the HIN and the hidden copy, make a tracing, tell your state agency, and keep the repair invoice. Afterward, reattach the number as permanently as the original.

Save copies of the application, inspection paperwork, the assigned HIN, your receipts and photos of the number on the boat. You'll need them for insurance, for a future sale, and if the boat is ever stolen; our theft prevention guide explains why photos of the HIN matter.