- An agreement between the US and Iran to reopen commercial transit through the Strait of Hormuz was announced on 15 June 2026, but sources close to the Government of Tehran do not confirm that payments for crossing have been excluded from the negotiations. The issue of charges remains formally open.
- Since late February 2026, following the US-Israeli attacks, Iran first blocked traffic de facto, allowing only selective passages in exchange for payments of up to two million dollars per ship, then attempted to formalise a toll based on cargo, at around one dollar per barrel of crude oil, to be paid in cryptocurrency.
- Legally, the 1982 United Nations Convention on the Law of the Sea, known as UNCLOS, allows fees for specific services provided to a ship, but prohibits charges imposed solely for transit. Studio Legale Zunarelli clarifies that the distinction between a “toll” and a “service charge” is central and that Tehran’s attempt to equate Hormuz with the Suez and Panama canals does not stand up under international law.
On 15 June 2026, Washington and Tehran announced that they had reached an agreement to restore the free movement of commercial vessels through the Strait of Hormuz. But for now, as the full text of the agreement is not known, a fundamental question remains open: the payment Iran is demanding from every vessel transiting the strait. There does not appear to be any agreement on this point: the president of the United States has stated that the agreement excludes any form of toll, while sources close to the Iranian Government leave the issue of payments open. The legal and operational knot, therefore, has not been untied. To understand the scale of the impasse, it is necessary to retrace the stages of a crisis that has developed over just a few months, with immediate repercussions for maritime transport costs and the strategies of logistics operators.
It all began between late February and early March 2026, when, in the wake of US and Israeli attacks on Iranian targets, Tehran announced the closure of the Strait and effectively suspended transit for most commercial vessels. Only ships from countries considered “friendly” - including China, India and Turkey - were able to pass, often in exchange for payments negotiated case by case and estimated, according to Lloyd’s reconstructions, at up to two million dollars for a single crossing. Several analysts have described this practice as the instrumental use of the Strait as a lever of economic and political pressure, in the absence of any transparent regulatory framework.
In the second half of March, the Iranian Parliament began examining a draft law to formalise a toll, with the official justification of funding security and control activities in the area. In April, Tehran approved a mechanism providing for cryptocurrency charges on loaded tankers, with an indicative rate of one dollar per barrel of crude oil or gas equivalent. The proposed operating procedure was basic but binding: each tanker would have to email the Iranian authorities with the characteristics of the vessel and its cargo, receive the amount due and payment instructions in digital currency, and pay the sum before beginning the crossing. The estimated impact of this measure is not negligible. International estimates by JP Morgan, meanwhile, put Tehran’s potential total revenues at between 70 and 90 billion dollars a year once fully operational: a figure that explains Iran’s political insistence on the matter.
Faced with growing criticism, Tehran’s messaging has gradually changed tone. The spokesperson for the Iranian Ministry of Foreign Affairs denied any intention to introduce tolls, saying Iran was merely collecting charges for “navigation services” and environmental protection measures in the Strait, the Persian Gulf and the Gulf of Oman. Tehran has also referred to an alleged cooperation protocol with Oman to guarantee safe passage, arguing that the payments requested would fall within the services offered by the two coastal states. For many observers, however, this is simply a change of label: the toll leaves through the door and returns through the window as a service cost, with no substantial change to the general and compulsory nature of the charge.
It is in this context that the assessment by Studio Legale Zunarelli fits, offering a systematic reconstruction of the applicable legal framework. The starting point is the 1982 United Nations Convention on the Law of the Sea, also known as the Montego Bay Convention or UNCLOS, which governs the navigation regime in “straits used for international navigation”, a category that unquestionably includes the Strait of Hormuz. Neither the United States nor Iran has ratified UNCLOS, but, Studio Legale Zunarelli notes, the convention is universally applicable because it codifies rules of customary international maritime law.
UNCLOS recognises the right of states to transit passage through international straits, under Article 38, paragraph 2. Iran argues that this regime applies, maintaining that the right of transit passage was a new concept introduced for the first time by UNCLOS and that, as it has not ratified the convention, it is not bound by it. Tehran nevertheless recognises the right of merchant ships to innocent passage through the Strait, defined as passage “which is not prejudicial to the peace, good order or security of the coastal State”, under Article 19. This right, however, is narrower than transit passage, with specific limitations for submarines, and may be restricted by the coastal state on matters of navigational safety and maritime traffic regulation.
The crucial point for the issue under discussion is Article 26 of UNCLOS. The provision states that “no charge may be levied upon foreign ships by reason only of their passage through the territorial sea”, while allowing charges “only as payment for specific services rendered to the ship”, with the obligation to apply them “without discrimination”. In practical terms, this means fees for pilotage or assistance services actually requested by ships are legitimate, but generalised tolls imposed solely for crossing are not, nor is differential treatment based on nationality. It is precisely this latter aspect - the preferential treatment reserved for vessels from “friendly” countries - that has most exposed Iran’s claims to international criticism.
Studio Legale Zunarelli also dismantles the comparison with the Suez and Panama canals, which is sometimes invoked to legitimise Iran’s position. The legal distinction is clear: Hormuz is a strait, a natural arm of the sea linking maritime spaces; Suez and Panama are artificial canals, classified as internal waters and therefore subject to the full sovereignty of the state in whose territory they are located. The coastal state of a canal can freely establish the conditions for crossing, including tariffs, whereas the coastal state of an international strait cannot, at least not without violating the rules of the law of the sea. The comparison, therefore, does not hold.
The position of the international community is broadly uniform. A spokesperson for the European Commission reiterated that international law guarantees freedom of navigation in the Strait of Hormuz, specifying that this means “basically no payment or toll of any kind” for crossing. The United States has insisted on the illegitimate nature of the tolls and on the risk that, if accepted, the Iranian model could create a precedent that could be replicated in other strategic maritime choke points, from the Strait of Malacca to the Strait of Gibraltar. The insurance sector has responded with a sharp increase in premiums for vessels in transit, while shipowners must simultaneously manage the risk of extra-contractual payments and possible breaches of international sanctions, especially for Western companies.
By mid-2026, the picture remains fluid. The implementation of Iran’s tariff mechanisms has been uneven: in many cases, transit has remained subject to contingent political decisions rather than a transparent tariff schedule. The announcement on 15 June opened a diplomatic window, but it has not yet produced an agreed text clarifying whether, and to what extent, transit payments have been formally excluded. For logistics operators and shipowners, operational uncertainty remains the hardest variable to manage.
M.L.
