Flag State and Flags of Convenience (Open Ship Registries)

Every merchant ship must be registered in one country, just like every car must have a number plate from one state. That country is called the ship's flag state. The ship flies that country's flag and follows that country's laws. When a ship is registered in a country that has no real connection to the owner, mainly to save money or face lighter rules, the practice is called using a flag of convenience. Countries that register foreign-owned ships freely are called open registries.

Why does a ship need a flag at all?

On the high seas (the open ocean beyond any country's control), there is no local police. Someone must be responsible for each ship. The flag answers that question. The flag state:

• decides who can register a ship and gives it nationality;
• inspects the ship and issues its safety and pollution certificates;
• checks that the crew are trained and properly treated;
• investigates accidents involving its ships;
• has legal control (jurisdiction) over the ship on the high seas.

A ship with no flag is called stateless. It has no protection and can be stopped and boarded by warships of any country.

What does international law say?

The main rules are in the UN Convention on the Law of the Sea (UNCLOS), 1982:

• Article 91 (nationality of ships): Every country can decide its own conditions for registering ships. Ships have the nationality of the country whose flag they fly. And there "must exist a genuine link" between the country and the ship.
• Article 92 (status of ships): A ship can sail under the flag of only one country. It cannot change its flag during a voyage or while in port, except when there is a real change of owner or registry. A ship that uses two or more flags as it likes may be treated as a ship with no nationality.
• Article 94 (duties of the flag state): Every flag state must effectively control its ships in administrative, technical and social matters. This includes ship safety, crew training and working conditions.

Where did flags of convenience come from?

Panama began registering foreign-owned ships in the early 20th century, and many American owners moved ships there to cut costs. Liberia started its ship registry in 1948, under President William Tubman, with help from Edward Stettinius, a former US Secretary of State. It was designed from the start to attract foreign ship owners. Since 1999, the Liberian registry has been managed by a private company, the Liberian International Ship and Corporate Registry (LISCR), based in the state of Virginia in the United States.

In the same year, 1948, the International Transport Workers' Federation (ITF), a global union of transport workers, launched its campaign against flags of convenience at its congress in Oslo.

How does an open registry work?

Imagine a shipping company based in Greece or Singapore. It could register its ship at home, but that may mean higher taxes, higher crew wages, and strict rules on the nationality of the crew. Instead, it registers the ship in an open registry. It pays a registration fee and a yearly tonnage tax, often done online through an office in another country. The owner can now:

• pay lower or no income tax;
• hire crew from any country, often at lower wages;
• sometimes keep the real owner's name hidden behind a shell company.

This is why it is called a "flag of convenience": it is convenient for the owner.

Who are the biggest registries?

As of 2026, the three largest registries are all open registries:

• Liberia: the largest in the world. It crossed 300 million gross tons in 2026, with about 5,900 ships. It overtook Panama in 2023.
• Panama: second largest.
• Marshall Islands: third largest.

Together these three carry nearly half of all world tonnage. None of them is a big ship-owning nation. The ITF keeps its own list of countries it treats as flags of convenience.

India's position and Indian examples

• India runs a closed or national registry. Earlier, under the Merchant Shipping Act, 1958, only Indian citizens, Indian companies and cooperative societies could own Indian-flagged ships.
• The Merchant Shipping Act, 2025 replaced the 1958 Act. It widens who can own an Indian ship to include Non-Resident Indians (NRIs) and Overseas Citizens of India (OCIs). It also allows ships taken on bareboat charter-cum-demise (a lease where ownership finally passes to the Indian party) to fly the Indian flag. The aim is to grow India's own fleet, because most of India's trade is carried by foreign-flagged ships.
• India also acts as a port state. It is a member of the Indian Ocean Memorandum of Understanding on Port State Control (IOMOU), whose secretariat is in Goa. Under it, member countries inspect foreign ships in their ports.
• Indian seafarers very often work on foreign-flagged ships. So when such a ship is attacked or its crew is abandoned, the flag state (not India) has the first legal responsibility. India then works through diplomacy to help its citizens.

Commonly confused concepts

• Flag state vs port state vs coastal state: The flag state is where the ship is registered. The port state is the country whose port the ship is visiting; it can inspect and detain unsafe ships. The coastal state is the country whose sea areas (territorial waters, EEZ) the ship is passing through.
• Flag state vs owner's country: A ship "Liberian-flagged" is not necessarily owned by Liberians. The owner may be in Greece, Japan, China or anywhere else.
• Open registry vs second registry: A second (or international) registry is a special register set up by a traditional maritime country to keep ships under its own flag with lower costs, for example Norway's International Ship Register. An open registry accepts ships from owners anywhere with no real link.
• Flag of convenience vs "dark fleet" or "shadow fleet": A flag of convenience is legal. The "shadow fleet" refers to ageing tankers that often hide their ownership, switch flags repeatedly, turn off tracking and move cargo under sanctions. Many of these use weak or fraudulent registries, but not every flag-of-convenience ship is part of a shadow fleet.
• Genuine link in theory vs practice: In the M/V Saiga (No. 2) case (1999), the International Tribunal for the Law of the Sea (ITLOS) rejected Guinea's argument that it could refuse to recognise a ship's flag (Saint Vincent and the Grenadines) because there was no genuine link. So in practice, a missing genuine link does not cancel a ship's nationality.

Issues, criticism and the way forward

• Weak control: Critics, especially seafarers' unions, say some open registries do not properly inspect ships or protect crews, even though Article 94 of UNCLOS requires it. This can lead to unsafe ships and abandoned crews.
• Hidden ownership: Shell companies can hide the true owner. This makes it harder to fix responsibility after an accident, to collect unpaid wages, or to enforce sanctions.
• Loss of tax and control for traditional maritime nations: Countries whose companies own the ships lose tax income and control.
• The other side: Large open registries such as Liberia and the Marshall Islands argue that they follow IMO rules, have good port state control records, and offer efficient, modern services. Not all open registries are low-quality.
• Way forward: Experts suggest defining the "genuine link" more clearly, stronger IMO audits of flag states, tougher port state control, IMO rules against fraudulent registration, and making the real owner of each ship public.

Concepts to Know

• High seas: The parts of the ocean outside any country's EEZ. No country owns them, and ships of all countries can sail there freely.
• Jurisdiction: The legal power of a country to make and enforce laws over something, such as a ship.
• Tonnage tax: A tax on ships based on their size (tonnage), not on the company's actual profits. It is usually lower and simpler than normal company tax.
• Shell company: A company that exists mainly on paper, with no real business, often used to hide who the real owner is.
• Bareboat charter: Hiring a ship without crew. The person who hires it runs the ship fully, as if they owned it for that period.
• Sanctions: Penalties, such as trade bans, that one or more countries put on another country, company or person.