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Iran’s strait toll violates law, nautical customs

The UNCLOS Articles 38 and 44 grant transit passage to all global shipping, which is defined as the exercise of the freedom of navigation

Updated on: Apr 11, 2026, 10:23:39 IST
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US President Donald Trump has warned Iran against collecting toll from commercial shipping passing through the contested Strait of Hormuz, as legally, Tehran claiming $2 million transit dollars from vessels contravenes the UN Convention on Laws of the Seas (UNCLOS).

Cargo ships in the Gulf, near the Strait of Hormuz, as seen from northern Ras al-Khaimah, near the border with Oman’s Musandam. (Reuters)
Cargo ships in the Gulf, near the Strait of Hormuz, as seen from northern Ras al-Khaimah, near the border with Oman’s Musandam. (Reuters)

While the Strait of Hormuz has become the bone of contention between US and Iran, with the latter using the vital lane of energy communication as a chokehold on global energy supplies, Article 38 of the UNCLOS makes the legal position in favour of those countries, including India, demanding unimpeded freedom of navigation and global flow of commerce through the narrow channel.

Even though Iran and Oman retain sovereignty over their respective territorial seas, the law (Article 38 of UNCLOS) stipulates that the sovereignty is limited by the “right of passage” enjoyed by all ships and aircraft in straits used for international navigation. Article 44 of the UNCLOS prescribes that the passage must be continuous and expeditious and will not be impeded by States bordering the strait.

HT graphic
HT graphic

The fact is that Iran signed UNCLOS in 1982 but did not ratify it, inferring that it is not directly bound by its provisions. However, Iran recognises some principles of UNCLOS like 12 nautical miles of territorial seas (TS) but rejects the full transit passage regime which allows free navigation through the Strait of Hormuz. Oman is a party to UNCLOS, having ratified in 1989.

Notwithstanding, apart from conventions, international law is governed by the customary practices also. And therefore, the issue is subject to interpretation. Naval law and treaty experts told Hindustan Times that if not through UNCLOS, Iran is bound by customary international law and hence charging toll from vessels is against accepted norms. “Apart from the US and Israel no one bombed Iran, so why should they pay toll to Tehran for passing through an international channel of water. It is a Strait, not a man-made canal. Further, 20% of global energy supplies go through the Strait to all over the world. Today it is Iran, tomorrow maybe China will charge a toll on vessels passing between the Communist country and Republic of Taiwan or the South China Sea,” said a top official.

Also Read:India rolls back some LPG curbs, allots more gas to fertiliser plants

During the 40-day war, Iran has used the Strait of Hormuz as a choke-point and as a leverage against the US, apart from making Persian Gulf countries collateral damage in the war.

The Strait of Hormuz comprises the territorial seas of Islamic Republic of Iran (North) and Sultanate of Oman (South). The strait is approximately 21 nautical miles wide at its narrowest point, which means that territorial seas of the two bordering nations overlap each other.

The UNCLOS Articles 38 and 44 grant transit passage to all global shipping, which is defined as the exercise of the freedom of navigation and overflight for the purpose of transit. UNCLOS restricts the authority of coastal states to regulate such transit and intervene, by stating that the passage of vessels shall not be impeded and there shall be no suspension of transit passage.

There are, however, restrictions imposed by UNCLOS, 1982, on transit passage. These are:

The transit passage must be continuous and expeditious.

Transiting ships must comply with the accepted international regulations, procedures and practices for safety at sea and for the prevention, reduction and control of pollution.

Ships exercising the right of transit passage must proceed without delay through the strait, must not engage in any research or fishing activities and must refrain from any threat or use of force.

Over the past decades, International Maritime Organization’s regional traffic separation scheme (TSS) has operated within the Strait of Hormuz to manage the high volume of tanker traffic — as many as 135 tankers cross it on a normal day. Iran in the past has respected the TSS to manage traffic. But on March 26, Iran established a de facto IRGC controlled shipping corridor in the Strait requiring only so-called approved vessels transit the narrow channel in Iranian waters. With the IRGC having military facilities on Qeshm Island in the Strait, global commercial shipping is at mercy of the Islamist regime despite the IMO criticising the Iranian moves.

The Iranian unilateral move is not only aimed at administering pain to global energy security but also the global economy as choking the Strait of Hormuz is leading to a spike in oil, LPG and LNG prices and is also dampening global market sentiments. Despite both Iran and the US declaring a ceasefire on Wednesday, Iran has only allowed eight of its own cargo vessels to pass through the strait. Such moves are not only discriminatory but also hold ominous portents for the future of commercial oil shipping.

  • Shishir Gupta
    ABOUT THE AUTHOR
    Shishir Gupta

    Shishir Gupta is Executive Editor at Hindustan Times and one of India's top journalists covering national security, strategic affairs, foreign policy and geopolitics. Over the past three decades, he has extensively reported on India's military, diplomatic and security landscape, covering every major conflict and national security challenge, from the 1999 Kargil War and the 2020 East Ladakh standoff to Operation Sindoor in 2025. He has also covered major terror attacks, including the IC-814 hijacking, the 26/11 Mumbai attacks and the 2025 Pahalgam terror strike, along with numerous Pakistan-backed terrorist incidents in the Kashmir Valley and across India. He has reported on national and state elections for more than three decades. A recognised authority on strategic affairs, Gupta has covered India's nuclear programme since the Pokhran-II (Shakti series) tests in May 1998 and has written extensively on global nuclear issues, Indian diplomacy and the country's expanding global outreach. He has also reported widely on international conflicts and terrorism, with a special focus on the Indian subcontinent. Gupta has interviewed Prime Minister Narendra Modi more than four times, including Modi's first interview with the print media after becoming Prime Minister in May 2014. His other interviews include three with the Dalai Lama, as well as conversations with Benjamin Netanyahu, Amit Shah, Yogi Adityanath, S. Jaishankar, Nirmala Sitharaman and Piyush Goyal. He is the author of Indian Mujahideen: The Enemy Within (Hachette, 2011) and Himalayan Face-off: Chinese Assertion and Indian Riposte (Hachette, 2014). He was awarded the Chevening-Wolfson Joint Scholarship at Wolfson College, University of Cambridge, UK, in 1998 and participated in the International Visitor Leadership Program (IVLP) of the US State Department in 2006. He received the Ben Gurion Prize from Israel in 2011 and the K. Subrahmanyam Prize for Strategic Studies in 2015 from the Manohar Parrikar Institute for Defence Studies and Analyses (MP-IDSA). Since 2024, he has hosted Point Blank, Hindustan Times' weekly YouTube show on global geopolitics.Read More

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