Montana Boat & Trailer Registration: Requirements & Fees

Montana boat and trailer registration requirements and fees are straightforward, but the rules depend on what you own and how you use it. If you’re planning to launch a motorized boat or tow a trailer on Montana roads, you need to know where to register, what documents to bring, and how much it will cost. This guide breaks down the process step by step.

As of 2026, a standard one-year boat registration for a vessel under 16 feet runs $21, while trailers are priced by weight.

Quick Answer: Who Must Register and Who’s Exempt

Most motorized boats and all trailers need registration in Montana. Non-motorized boats under 12 feet are exempt. Registration fees vary by boat length and trailer weight.

You can register online, by mail, or at a county motor vehicle office.

Do You Need to Register Your Boat or Trailer in Montana?

If your boat has a motor, you must register it. Montana law requires registration for all motorized vessels, including outboards, inboards, and sailboats with auxiliary engines. The only common exemption is for non-motorized boats under 12 feet, like kayaks or canoes.

Add a trolling motor, and registration becomes mandatory.

Trailer registration is separate. Every trailer used on Montana roads must be registered, whether it’s carrying a boat, utility load, or other cargo. Weight matters: trailers over 3,000 pounds GVWR require a title and license plates.

Here’s a quick decision guide:

• Motorized boat? Register with Montana Fish, Wildlife & Parks (FWP).
• Non-motorized boat under 12 feet? No registration required.
• Boat over 12 feet, non-motorized? No registration, but you may want a title for proof of ownership.
• Trailer of any size? Register and plate it at your county motor vehicle office.
• Trailer over 3,000 lbs GVWR? Title and plates are mandatory.

When in doubt, register. Fines for unregistered boats or trailers can exceed the cost of registration.

How Montana Boat Registration Works

Boat registration in Montana is handled by the Montana Fish, Wildlife & Parks (FWP) division. You’ll receive a decal to display on the vessel and a certificate of registration to keep on board.

To register a boat, you’ll need:

• A completed Application for Boat Registration (FWP form)
• Proof of ownership (title, bill of sale, or previous registration)
• A valid photo ID
• Payment for the registration fee

If your boat was built before 1972, it may lack a Hull Identification Number (HIN). FWP will assign one after a physical inspection.

Montana also requires an invasive species decal for most motorized boats. This decal helps fund clean-boat initiatives and prevents the spread of zebra mussels and other invasive species.

How Montana Trailer Registration Works

Trailer registration falls under the Montana Motor Vehicle Division (MVD). Unlike boat registration, trailer registration is processed through your county treasurer’s office or MVD station. You’ll receive license plates and a registration card.

Requirements depend on the trailer’s Gross Vehicle Weight Rating (GVWR):

• GVWR under 3,000 lbs: Registration only, no title required in many cases.
• GVWR 3,000 lbs and above: Title and registration are both required.

You’ll need to provide:

• Proof of ownership (title or bill of sale)
• A completed Application for Trailer Title and Registration
• A valid ID
• Payment of the registration fee, which is based on weight

If you’re titling a trailer for the first time, you may need an inspection to verify the VIN. This is especially common for homemade or older trailers.

Step-by-Step: Registering a Boat in Montana

1. Gather your documents

Collect your proof of ownership (title or bill of sale), a photo ID, and your boat’s HIN if applicable. If the boat is used, have the previous owner’s release of liability ready.

2. Complete the application

Download the form from the Montana FWP website or pick up a paper copy at a county office. Fill it out completely.

3. Pay the fee

Fees vary by boat length. As of 2026, registration for a boat under 16 feet is $21 for one year. You can pay online, by mail, or in person.

4. Receive your decal and certificate

Once processed, you’ll get a registration certificate and a decal. Affix the decal to the starboard (right) side of the bow, within 6 inches of the top edge. Keep the certificate in the boat when you’re on the water.

5. Add the invasive species decal

If your boat is motorized, you’ll also receive an invasive species decal. Stick it on the hull near the registration decal.

Step-by-Step: Registering a Trailer in Montana

1. Determine your trailer’s weight class

Check the GVWR on the trailer’s certification label. This determines whether you need a title and what fee bracket you fall into.

2. Get proof of ownership

If the trailer has a title, make sure it’s signed over to you. If it’s a homemade trailer, you’ll need a bill of sale and possibly a form from the MVD.

3. Fill out the application

Use the form from the Montana MVD. You can submit it online, by mail, or in person at your county treasurer’s office.

4. Pay the registration fee

Fees are based on trailer weight. A utility trailer under 2,000 lbs might cost around $15, $20 for a year’s registration. Heavier trailers cost more.

5. Receive plates and registration card

Once approved, you’ll get license plates and a registration card. Mount the plates on the rear of the trailer. Keep the registration card with your vehicle papers.

6. Pass inspection if required

For trailers over 3,000 lbs GVWR or those without a title, an MVD inspection may be necessary. This verifies the VIN and ensures the trailer meets safety standards.

Montana Boat and Trailer Registration Fees (2024)

Fees are based on vessel length and trailer weight. For boats, the cost starts at $21 for vessels under 16 feet and increases with size. Trailers are priced by GVWR, with lighter models costing less.

Here’s a quick breakdown of common fees as of 2026:

Non-residents pay the same base fees but may need a temporary permit for short-term use. The invasive species decal adds $10 for residents and $30 for non-residents.

Non-Residents: Temporary Permits and Short-Term Rules

Non-residents can use Montana waters for up to 60 consecutive days without full registration. After that, you must register the boat in Montana or obtain a temporary permit.

The temporary permit costs $25 for 30 days or $50 for 60 days. It covers motorized and non-motorized boats but does not include the invasive species decal, which is required separately.

If you’re towing a trailer, standard Montana registration rules apply regardless of residency. Trailers must be registered if used on public roads.

Transferring Ownership or Moving to Montana

When you buy a used boat or trailer, you have 30 days to transfer the registration into your name. For boats, submit the signed title or previous registration along with a bill of sale to FWP. For trailers, visit your county treasurer’s office with the title and proof of purchase.

New Montana residents must register their boats and trailers within 60 days of establishing residency. You’ll need to provide proof of ownership and pay the standard fees. If your boat was registered in another state, you may need to pass an inspection to verify the HIN.

Homemade boats and trailers require additional steps. For boats, FWP will assign a HIN after inspection. For trailers, the MVD may require a VIN inspection before issuing a title.

Common Mistakes That Lead to Fines or Delays

Forgetting to display the decal is a common error. The registration decal must be visible on the starboard side of the bow, and the invasive species decal must be placed nearby. Both should be affixed above the waterline.

Another frequent issue is letting registration lapse. Operating an unregistered boat or trailer can result in fines up to $500. Renewals are due by the last day of the month listed on your registration certificate.

Mismatched information is also a problem. Ensure the name and address on your registration match your ID. If you’ve moved or changed your name, update your registration within 10 days.

Renewing Your Registration (And What Happens If You Don’t)

Renewals can be done online, by mail, or in person. FWP sends a renewal notice about 60 days before expiration, but it’s your responsibility to renew on time even if you don’t receive one.

Late fees apply after the expiration date. For boats, the penalty is $10 for the first 30 days and $20 after that. Trailers incur a $10 late fee regardless of duration.

You can renew for one or three years. The three-year option saves time and a bit of money but requires upfront payment.

Where to Register: Online, Mail, or In-Person

You can register a boat online through the Montana FWP website. The portal accepts credit card payments and processes applications quickly. You’ll receive a temporary registration immediately to print and use until your decals arrive by mail.

For mail-in registration, send your completed application and payment to the FWP headquarters in Helena. Processing takes about 10 business days. Include a self-addressed stamped envelope if you want your decals mailed back faster.

In-person registration is available at county treasurer offices and some FWP regional offices. This is the fastest option if you need your registration immediately. Bring all required documents and payment to avoid delays.

Montana’s Extra Rules: Decals, Inspections, and Invasive Species

All motorized boats must display two decals: the registration decal and the invasive species decal. The registration decal goes on the starboard side of the bow. The invasive species decal can be placed anywhere on the hull but must be visible.

Inspections are required for homemade boats and some out-of-state vessels. FWP or MVD will verify the HIN or assign one if missing. Trailers over 3,000 lbs GVWR may also need a VIN inspection before titling.

Montana takes invasive species seriously. The invasive species decal is mandatory for all motorized boats, including those registered out of state but used in Montana. The fee funds inspection stations and education programs to prevent the spread of aquatic nuisance species.

Frequently Asked Questions