The current framework

Public statements following the 14 June 2026 US-Iran memorandum suggest that Tehran is treating the current reopening of the Strait of Hormuz as an interim arrangement tied to negotiations, not as a permanent return to unrestricted navigation. The critical issue is whether any future Iranian charges can credibly be characterised as payment for genuine maritime services, rather than as unlawful tolls on transit through an international strait.

The reporting available to date indicates that the June memorandum provides for the reopening of the Strait in the short term, but does not settle the longer-term legal and operational framework governing passage. It’s been extensively reported that whilst the agreement allows immediate reopening, it leaves important details unresolved, with major points of implementation deferred to a further negotiation round.

 Against that backdrop, Iranian officials have rejected the suggestion that the Strait is now simply “fully open”, instead presenting the present situation as one of managed access under continued Iranian supervision. Although rhetoric referring to “smart control” appears in Iran’s broader naval security messaging, the more legally relevant point is that Tehran is framing the current arrangement as conditional and revocable, not as an acknowledgment of unrestricted transit as a practical matter.

Transit and service fees

The law governing international straits sharply limits the ability of coastal states to obstruct or monetise passage. Ships enjoy a right of transit passage through straits used for international navigation. States bordering such straits may not hamper or suspend that right.

 However, whilst a state cannot lawfully impose a toll merely for the act of passage, charges for specific services actually rendered may be permissible in some circumstances.

It is precisely this legal distinction that appears to be shaping Tehran’s public position. Iranian statements reported in June indicate that vessels may transit without charge during a 60-day negotiation period, after which Iran may seek compensation for navigation support, environmental protection, insurance, safety, or related maritime functions. The evident purpose of this formulation is to avoid describing the payment as a toll, because a direct charge for the right to cross the Strait would face serious objections under the established law of transit passage. The legal vulnerability, however, is that international law generally looks to substance as well as label: a fee described as payment for services may still be challenged if, in reality, it functions as a compulsory charge imposed simply for access to the waterway rather than for an identifiable and optional service rendered to the vessel.

Criteria for assessing any future charging regime

For that reason, any future Iranian charging scheme would likely be assessed against several practical legal criteria.

1.      The first is whether the charge is linked to a concrete service actually provided to the ship, rather than to navigation through the Strait as such. 

2.      The second is whether the fee structure is transparent, non-discriminatory, and predictable, rather than discretionary or politically conditioned.

3.      The third is whether compliance is framed as mandatory for passage itself; if payment is required in order to secure permission to transit, the regime may be viewed less as a service arrangement and more as a licensing system incompatible with the right of transit passage. Even on the more permissive reading of the law, a charge for pilotage, traffic management assistance, pollution response capacity, or similar functions is easier to defend than a generalised requirement that all vessels pay for safe passage through a waterway that international law treats as open to continuous and expeditious navigation.

Commercial and regional implications

Another legal complication is the uncertain relationship between sovereignty claims, enforcement practice, and the operational role of non-civilian actors. Iranian messaging has emphasised the role of the IRGC Navy in overseeing conditions in and around the Strait, but from a commercial law perspective the identity of the enforcing authority may matter less than whether the regime is administered through clear legal rules capable of consistent application. 

Shipping interests, insurers, and P&I clubs will be concerned not only with the formal legality of any announced fee, but also with how it is documented, who collects it, what consequences attach to non-payment, and whether those consequences include delay, rerouting, detention, or denial of passage. In other words, we expect the market to react to ambiguity even before the legal validity of any Iranian fee structure is tested in any diplomatic or judicial fora. 

Iran may seek a more durable management framework, potentially in coordination with Oman, which adds a further layer of complexity. Cooperative administration of maritime services is not inherently inconsistent with international law, but any bilateral or regional arrangement would still remain subject to the basic rule that the right of transit passage through an international strait cannot be converted into a revenue-generating permission system. 

That is why comparisons to regulated waterways elsewhere should be treated with caution; not every chokepoint is governed by the same treaty history, navigational regime, or customary law status, and analogies may obscure as much as they clarify.