MMSI Number Transfer When You Sell Your Boat

28 August 2026 6 minutes Tags:

Selling your boat? Your MMSI number does not stay with the boat. An MMSI is tied to the flag state, not the vessel. So when ownership changes, the new owner usually needs a new MMSI number.

What Is an MMSI Number?

An MMSI (Maritime Mobile Service Identity) is a unique nine-digit number. It identifies your boat on radio and AIS systems. A marine radio licence is a legal document that authorizes you to operate radio equipment on your boat. You must keep this licence on board at all times.

MMSI Is Tied to the Flag, Not the Boat

Many owners think the MMSI stays with the boat. It does not. The MMSI is tied to the flag state and the radio licence. If you sell your boat or change its flag, you usually need a new MMSI number. The IMO number is different. It stays with the vessel for its whole life.

When You Sell Your Boat: Transfer Rules

When you sell your boat, the MMSI does not transfer to the new owner. For example, a UK MMSI cannot be transferred between owners. The old licence must be deleted, and the new owner must apply for a completely new MMSI, AIS number, and call sign. The same principle applies to most flag states.

Keeping the Same Flag vs. Changing Flag

If the new owner keeps the boat under the same flag state, they still cannot take over your MMSI. They must apply for a new MMSI from that flag’s authority. If the new owner changes the vessel’s flag registration, the MMSI typically needs to be updated to match the new flag state. In both cases, a fresh application is required — the MMSI never follows the boat or the previous owner.

When Is an MMSI Required?

An MMSI is generally required for boats equipped with VHF radio or AIS, particularly for commercial use, international voyages, or vessels above certain sizes. For recreational boats used only in domestic waters, requirements vary by flag state. BlueWater can advise whether your situation calls for an MMSI and which flag state offers the most practical solution.

BlueWater’s MMSI Services: Fast and Flag-Specific

BlueWater offers MMSI radio licences for the flag states we register: the Netherlands, Poland, and the UK. Each flag state has its own processing characteristics. A Dutch MMSI can be delivered within 24 hours, while a Polish MMSI applied for together with Polish boat registration takes up to eight weeks. Waiting times vary by flag state; BlueWater advises you on the fastest option for your situation.

Some radio licences, like those from the Netherlands and Poland, are only available when you register your boat with the same country’s registry. BlueWater can combine your MMSI application with a new boat registration under your chosen flag, ensuring everything is aligned. For example, a Dutch MMSI licence combined with a Dutch Zeebrief registration costs €150, while the standalone Dutch MMSI licence starts from €250. The MMSI radio licence and AIS number package costs €350, or €250 when combined with certain registrations. All prices exclude 21% VAT; non-EU clients are not charged VAT where applicable, depending on their residency status and the import status of the vessel.

What to Do When You Change Flag or Ownership

If you change your boat’s name or ownership, you must update your MMSI registration. If you change the vessel’s flag registration, your MMSI typically needs to be updated to match the new flag state. Always inform the relevant authority or your registration service about any changes.

How to Get a New MMSI Quickly

If you are the new owner, you need to apply for a fresh MMSI. BlueWater can deliver a new MMSI radio licence within 24 hours for eligible flag states. The package includes the MMSI and AIS numbers, a unique call sign, and official documentation. The standalone package costs €350. If you combine it with a boat registration, the price drops to €250. All prices exclude 21% VAT. Non-EU clients are not charged VAT where applicable.

Why Choose BlueWater for Your MMSI Application

BlueWater checks your documents to prevent delays, communicates with authorities on your behalf, and delivers official certificates worldwide. This means you avoid the back-and-forth that often slows down direct applications. We handle the entire process from start to finish, so you receive a legally valid licence without the administrative burden.

Documents You Need for an MMSI Application

To apply for an MMSI, you typically need proof of vessel ownership, boat registration details, a completed application form, and a copy of your passport or ID. You also need operational information like primary cruising area, home port, and intended use. Provide emergency contact details, including full name, phone number with country code, and relationship to the owner. You must list radio equipment details, such as VHF make and model, AIS transponder, and EPIRB if installed. Vessel technical details are required too: length overall in meters, vessel type, year of build, HIN, engine details, and construction material. Include a copy of the current registration certificate, bill of sale, and builder’s certificate if available.

BlueWater Handles the Whole Process

BlueWater manages MMSI applications from start to finish. We check documents to avoid delays, liaise with authorities, and deliver official certificates worldwide. We serve customers from all over the world, and the entire process is in English. You can apply online.

Summary

Your MMSI number does not transfer with the boat when you sell it. It is tied to the flag state, so the new owner needs a new MMSI. BlueWater can issue a new MMSI licence quickly, often within 24 hours for eligible flag states. Contact BlueWater for a fast MMSI application — we handle everything and deliver your licence promptly, combined with your new boat registration.

Frequently asked questions

Can I transfer my MMSI to the new owner when I sell my boat?

No. An MMSI is tied to the flag state, not the boat. It does not stay with the boat when sold. The new owner must apply for a new MMSI.

What happens to my MMSI if I change the flag of my boat?

Your MMSI typically needs to be updated to match the new flag state. You will likely need a new MMSI number from the new flag’s authority.

Which flag state has the fastest MMSI processing?

BlueWater offers MMSI licences for the Netherlands, Poland, and the UK. A Dutch MMSI can be delivered within 24 hours, while a Polish MMSI applied for with Polish registration takes up to eight weeks. Waiting times vary by flag state; BlueWater advises you on the fastest option for your situation.

How much does a new MMSI licence cost?

A standalone MMSI package from BlueWater costs €350. If you combine it with a boat registration, the price drops to €250. A Dutch MMSI combined with a Zeebrief costs €150. All prices exclude 21% VAT.

How long does it take to get a new MMSI licence?

BlueWater can deliver a new MMSI radio licence within 24 hours for eligible flag states, such as the Netherlands. Other flag states may take longer; BlueWater advises on realistic timelines for your chosen registration.

What documents do I need to apply for an MMSI?

You need proof of vessel ownership, boat registration details, a completed application form, and a copy of your passport or ID. You also need operational, emergency contact, radio equipment, and vessel technical details.

Trusted Experience in International Yacht Registration

For more than 18 years, BlueWater Registration Services has helped private and commercial yacht owners navigate international registration and documentation requirements. Our experienced specialists provide personal support, practical guidance and clear communication throughout the registration process.

We assist clients worldwide and are available seven days a week. Whether you are registering a yacht, changing flag or purchasing a vessel abroad, our team can help you identify the most suitable registration options for your circumstances.

Speak directly with a yacht registration specialist.

Facts checked and up to date as of 28 August 2026.