• The US Treasury issued sanctions guidance warning that payments to Iran or the IRGC for safe passage through the Strait of Hormuz could trigger sanctions against shipowners, banks, insurers, and other foreign counterparties.
  • Iran has floated or implemented toll concepts for vessels traversing the Hormuz corridor, including rial-based tolls and selective restrictions, raising concerns about access for US- and Israel-linked vessels.
  • The evolving toll regime and sanctions guidance heighten compliance risk for global shipping, potentially narrowing routes and increasing freight costs as operators reassess exposure to Iran-linked payments.

Sanctions Guidance Escalates Compliance Risk

The US Treasury’s Office of Foreign Assets Control (OFAC) issued fresh sanctions guidance this week, cautioning that any payments related to tolls or safe passage through the Strait of Hormuz could expose shipowners, banks, insurers, and trading houses to US sanctions. The move targets Iran’s attempts to monetize the strategic chokepoint, which handles about 20% of global oil consumption.

“This is a significant escalation in enforcement posture,” said a commodities compliance officer at a European bank, requesting anonymity. “Before, the risk was more theoretical. Now, OFAC is explicitly saying: if you pay, you’re in the crosshairs.”

Iran’s Toll Proposals Raise the Stakes

Iran has been advancing plans to impose tolls on vessels traversing the strait, including a rial-based fee system and potential restrictions on ships flagged to or linked with the US and Israel. According to reports from Gulf shipping sources, Iranian port authorities have begun informal checks and selective denial of services to vessels they deem noncompliant.

The toll concept remains in flux—some sources describe it as a "corridor fee" that includes escort services—but industry analysts warn the uncertainty alone is disruptive. “Even a rumor of a toll makes insurers nervous and banks cautious,” said a London-based shipping lawyer. “We’re already seeing higher premiums for Gulf transits.”

Market Impact and Industry Response

The sanctions guidance and toll talk are already moving markets. Spot freight rates for supertankers have ticked up as charterers seek routes that avoid Hormuz or secure additional insurance. Brent crude spiked briefly above $80 per barrel on the news before settling, suggesting the geopolitical premium is widening.

Major tanker operators are reassigning vessels. “Several clients have paused Gulf-bound charters pending legal review,” said a broker at a major shipbroking firm. Others are exploring alternative corridors, such as the Bab el-Mandeb, though that route carries its own security risks.

Legal and Diplomatic Dimensions

The US stance aligns with longstanding international law principles of freedom of navigation—enshrined in the UN Convention on the Law of the Sea—which Iran has questioned through its toll proposals. The International Maritime Organization has privately flagged concerns, but public statements remain muted due to diplomatic sensitivities.

Attempts to reach Iran’s mission to the UN for comment were unsuccessful. The US Treasury declined to elaborate on the guidance except to confirm it is “enforcement-focused.”

Looking Ahead

For shippers and their financiers, the immediate challenge is operational. Banks must now vet any payment that touches Iranian entities—including port dues, pilotage, or escort fees—as potentially sanctionsable. For now, the safest path is avoidance, but that brings its own costs.

“Compliance is the new form of volatility,” the European banker said. “We’re advising clients to treat every trip into the Gulf as a sanctions event until further notice.”

Correction: An earlier version of this article incorrectly stated that Iran had formally adopted a toll system. The article has been updated to reflect the proposals remain under discussion.