Indian refiners to avoid Iran blacklist tankers on security fears

Iran has previously attacked several of the tankers, including the Wedyan, Mombasa B and Al Bahyah.

Two of the 12 very large crude carriers on Iran's blacklist were no longer giving their location through their automatic identification systems by Tuesday after the list was released. The rest have had their AIS transponders switched off for weeks.

"The key issue is contagion," Kpler's Subasic said. If Iran follows through on threats to penalize vessels that conduct STS transfers with blacklisted tankers, that should narrow the pool of willing shipowners, charterers and buyers, particularly among firms with material Gulf exposure, while increasing due-diligence requirements and potentially freight, insurance and risk premia, she added.

The Indian refiners' decision mirrors a broader shift in the tanker market as traders and shippers weigh the cost of running afoul of Tehran's new enforcement regime. The blacklist targets vessels that have continued to move oil through the strait despite Iran's earlier warnings, and the threat of cargo confiscation raises the financial stake for anyone caught in a transfer.

For Indian buyers, who rely on Middle Eastern crude for roughly 60% of their imports, the immediate effect is a tighter pool of available tankers. The three refiners and the global major that spoke to this publication are among the largest regular charterers in the region. Their decision to blacklist the 45 vessels could push freight rates higher for compliant tonnage as demand for clean ships rises.

The rerouting Subasic described is already visible in the data. Several of the blacklisted VLCCs had already gone dark before the announcement, a sign that owners anticipated the move. The question now is whether the remaining compliant fleet can handle the volume without a spike in costs.

Iran's post on X said the listed vessels face fines, detention and cargo seizure. The Persian Gulf Strait Authority did not specify a timeline for enforcement. The Indian sources said their companies are treating the warning as credible given Iran's history of attacks on tankers in the waterway.

Formosa's Lin said the company is still assessing how to handle long-term crude deliveries through the strait. The Taiwanese refiner is one of the largest buyers of Gulf crude in Asia and relies heavily on STS transfers off Oman.

The blacklist adds a layer of compliance risk to an already complex trade route. Before the war, about 17 million barrels a day of crude and products moved through the Strait of Hormuz. The shuttle-and-STS system has kept a portion of that flowing, but each new Iranian threat raises the bar for participants.

For now, the Indian refiners' move is the clearest signal yet that the buyer side of the market is drawing a line. Whether other Asian importers follow will depend on how aggressively Iran enforces the new list and whether the remaining shuttle fleet can absorb the redirected volume.