Tehran has imposed a new clearance regime on ships navigating the Strait of Hormuz, demanding that all vessels submit detailed information to a newly created Iranian authority or risk being targeted. The move, confirmed by a document obtained by Lloyd’s List Intelligence and shared with international media, formalises what was previously an informal system of questioning and marks a significant escalation in Iran's effort to assert administrative control over one of the world's most strategic maritime chokepoints.

The document, titled 'Vessel Information Declaration', is issued by the newly established Persian Gulf Strait Authority (PGSA) and contains more than 40 questions. Masters are required to provide the ship’s name, identification number, previous names, country of origin and destination, as well as the nationalities of the registered owner, the manager and all crew members. The completed form must be emailed to the PGSA before transit. From Tehran’s perspective, this is an attempt to codify existing security checks; from Washington and London, it looks like a unilateral assertion of sovereignty over international waters.

Before the American and Israeli campaign against Iran that began in late February, the strait was open to all shipping without preconditions. Since then, Iran has threatened to strike any vessel that crosses without permission from the Islamic Revolutionary Guard Corps navy, and several ships have already been attacked. The new protocol appears designed to institutionalise that threat, turning a de facto blockade into a bureaucratic process that Iran can enforce selectively. Tehran has explicitly stated it will deny passage to any ship linked to the United States or Israel.

Viewed from the Gulf, the implications are immediate and unsettling. The strait handles about a fifth of the world’s oil supply, and any disruption sends tremors through global energy markets. Shipping executives now face a choice between complying with Iranian demands and risking sanctions or non-compliance and facing military retaliation. Analysts note that the PGSA’s questions resemble those already asked informally, but the formalisation creates a paper trail that could be used to detain vessels or crews for administrative violations. The international community, including the International Maritime Organization, has yet to issue a formal response, but the United States has warned that it will not accept Iranian restrictions on freedom of navigation.

Looking ahead, the new protocol risks deepening the confrontation in the Gulf. Iran is betting that the cost and inconvenience of compliance will deter the shipping industry from challenging its authority, while the US and its allies may respond by providing naval escorts or imposing countermeasures. The strait has long been a flashpoint, but by codifying its demands, Tehran is daring the world to either accept its new rules or force a crisis. For now, the shipping industry is left in an unenviable position: navigate a bureaucratic minefield or sail into a military one.