Iran’s blacklist is working — oil companies are now avoiding the ships

Iran threatened 45 tankers with fines, detention and cargo confiscation for allegedly breaking its Strait of Hormuz rules. Major oil buyers are now changing their behaviour. That matters because a rule does not need international acceptance to influence global trade if businesses decide the risk of ignoring it is too great.

Iran's attempt to exert control over shipping through the Strait of Hormuz has passed an important test.

Companies are beginning to behave as though its rules matter.

At least three Indian oil refiners and one major international energy company are preparing to avoid tankers included on Iran's recently announced blacklist of 45 vessels, according to Reuters.

The companies are not necessarily accepting Iran's legal claim to regulate international passage through the Strait.

They are doing something much more commercially significant.

They are deciding that using a blacklisted vessel may simply be too risky.

That distinction tells us a great deal about how economic power works around Hormuz.

Iran does not have to persuade the world that its rules are legitimate.

If it can persuade enough shipowners, charterers, refiners, banks and insurers that ignoring those rules could result in a tanker being detained or its cargo confiscated, commercial behaviour begins changing anyway.

The blacklist contains 45 ships

Iran announced the blacklist through its Persian Gulf Strait Authority, the organisation Tehran has established to administer its system for vessels using Hormuz.

Iran says the 45 vessels violated its transit requirements.

The threatened consequences are substantial.

They include:

• fines;
• detention;
• possible cargo confiscation;
• and potential action against other vessels conducting ship-to-ship transfers with blacklisted ships.

The vessels include crude, LNG, LPG and refined-product tankers.

Some have links to major regional and international shipping operations.

Iran has also indicated that shipowners can seek removal from the blacklist by providing explanations to Iranian maritime authorities.

That final detail is important.

A blacklist with an appeals process begins to look less like a wartime threat and more like an attempted regulatory system.

Until now, there was an obvious question

Would anyone outside Iran actually take it seriously?

Tehran can announce whatever shipping rules it chooses.

That does not automatically mean international companies will recognise them.

The Strait of Hormuz is an internationally important navigational route.

Iran's attempt to exercise unilateral authority over passage is deeply contested.

But a multinational energy company has another problem.

It owns, charters or relies upon extremely valuable ships and cargoes.

Its executives have obligations to shareholders.

Insurers have obligations to policyholders.

Banks have credit committees.

Shipowners have crews to protect.

The legal argument therefore becomes only one part of the calculation.

The other question is brutally practical:

What might Iran actually do to our ship?

Oil companies have begun answering that question

Reuters reports that three Indian refiners and a global energy major are preparing to avoid vessels on the Iranian list.

Taiwan's Formosa Petrochemical is also reconsidering aspects of its ship-to-ship transfer arrangements.

The immediate expectation is not that Gulf oil exports suddenly stop.

Companies can find replacement vessels.

Cargoes can be rearranged.

Different tankers can perform shuttle operations.

Alternative routes and transfer arrangements can be considered.

But every adaptation introduces friction into what was previously an extraordinarily efficient global logistics system.

And friction costs money.

The shuttle system matters

The blacklisted vessels are particularly important because of the extraordinary shipping system that has evolved during the Hormuz crisis.

Saudi Arabia, the United Arab Emirates and other Gulf producers need to move enormous quantities of energy from inside the Gulf to international customers.

But sending conventional long-haul tankers through Hormuz has become difficult and dangerous.

One solution has been the shuttle tanker.

A vessel loads oil inside the Gulf.

It makes the dangerous journey through Hormuz.

Then, once outside the highest-risk area, it transfers the cargo to another vessel.

That second tanker can take the oil onwards to customers in Asia or elsewhere.

This is known as a ship-to-ship transfer, or STS.

It is a clever adaptation.

It limits the number of long-haul international tankers that must enter the most dangerous waters.

Iran has targeted the workaround

That is what makes the blacklist particularly interesting.

Iran has not simply threatened the original vessels.

It has warned that ships transferring cargo with blacklisted tankers could themselves face consequences.

The risk can therefore propagate.

Imagine Tanker A is blacklisted.

Tanker B receives Tanker A's cargo outside the Strait.

Does Tanker B now face Iranian action on a future Gulf voyage?

What about Tanker B's insurer?

What about its next charterer?

What about the bank financing its next cargo?

What about another tanker that later conducts business with Tanker B?

Suddenly a list containing 45 vessels potentially affects considerably more than 45 vessels.

This is how commercial contagion works

A blacklist becomes powerful when companies begin asking not merely:

Are we on the list?

but:

Who have we done business with?

That produces additional due diligence.

Charterers examine vessel histories.

Insurers examine exposures.

Cargo traders examine previous ship-to-ship transfers.

Owners reconsider which vessels they will charter.

Banks may seek additional information before financing transactions.

Each company is protecting itself.

Collectively, those decisions can alter the market.

Iran does not need universal compliance

This is perhaps the most important point.

Suppose half the international shipping industry completely ignores Iran's blacklist.

But the other half decides the risk is unacceptable.

Iran has still changed the market.

The pool of commercially acceptable tankers becomes smaller.

Demand concentrates on vessels that have not been blacklisted.

Those vessels become more valuable.

Charter rates can rise.

Scheduling becomes more difficult.

Ship-to-ship transfer capacity becomes tighter.

And the cost of moving every barrel increases.

This is how a relatively small administrative action can produce consequences throughout a global commodity market.

Insurance magnifies the effect

Then comes insurance.

War-risk insurance around the Gulf has already become extraordinarily expensive.

An insurer assessing a voyage now has another potential hazard to consider.

Not simply:

Could this tanker be hit?

But:

Could this tanker be detained?

Could its cargo be confiscated?

Is it on an Iranian blacklist?

Has it previously transferred cargo with a listed ship?

Could Iran place it on the blacklist during the policy period?

These are not theoretical questions once commercial companies begin changing their operations in response.

Risk that was difficult to quantify has become behaviour that can be observed.

Insurers notice that.

Five ships crossed on Tuesday

Meanwhile, the physical evidence from Hormuz remains sobering.

Preliminary Kpler data recorded only five commodity vessels transiting the Strait on Tuesday.

That compares with a 10-day average of 15.

Two LPG tankers and a bitumen tanker exited the Gulf.

Two empty product tankers entered.

On Monday there were only four recorded commodity transits.

The figures can subsequently change because some ships turn off their AIS location transponders while travelling through the area.

That qualification is important.

But even allowing for dark shipping, transparent commercial traffic remains nowhere near normal conditions.

Iran and Oman are simultaneously talking about reopening

This produces an extraordinary contradiction.

Iran and Oman are discussing arrangements that could eventually restore more regular navigation through Hormuz.

The countries have explored a temporary joint shipping corridor.

Mine clearance is being discussed.

Technical arrangements for managing vessel movements are being considered.

Those are encouraging developments.

Yet at precisely the same time, companies are avoiding vessels because of Iran's blacklist.

Diplomacy is attempting to make Hormuz easier to use.

Commercial risk is still making it harder.

Both things can be true simultaneously.

This is why we should not declare Hormuz reopened

Removing mines is important.

Creating an agreed navigation corridor would be important.

Reducing military attacks would be enormously important.

But commercial confidence has to return as well.

An oil company considering a tanker voyage must evaluate the complete risk.

Physical danger.

Iranian enforcement.

US sanctions.

Insurance.

Crew safety.

Cargo security.

Financing.

Charter costs.

Potential delays.

Until those risks become manageable, a theoretically navigable Strait can remain commercially impaired.

The market is already responding to hopes of reopening

Interestingly, crude-oil markets have become more optimistic.

Brent crude fell more than US$2 a barrel as markets responded to the Iran-Oman talks and the possibility of progress towards restoring Hormuz navigation.

Brent traded around US$86.28 a barrel, while West Texas Intermediate fell to about US$80.29.

Those declines followed falls of more than 3 per cent in both benchmarks the previous day.

That tells us traders believe reopening is becoming more plausible.

But there is an important Australian warning.

A falling crude price does not automatically mean the fuel crisis has disappeared.

Australia buys finished fuel too

Australia relies substantially upon international markets for refined petroleum products.

Petrol.

Diesel.

Jet fuel.

These products require much more than crude oil.

They require functioning refineries.

Available product tankers.

Insurance.

Storage.

Freight.

Distribution.

And a commercially functioning regional shipping system.

If Iranian restrictions reduce the pool of tankers that companies are prepared to use, logistics remain expensive even if Brent crude falls.

Think of the tanker fleet as another commodity

We normally think of oil as the scarce product.

During a shipping crisis, the ship itself can become scarce.

There may be plenty of physical tankers in the world.

But that is not the relevant number.

The relevant number is:

How many suitable tankers are available, insured, acceptable to the charterer, acceptable to the cargo owner, compliant with sanctions and sufficiently free of Iranian enforcement risk to perform the voyage?

That pool can be dramatically smaller.

And when supply falls while demand remains high, the price of tanker capacity rises.

The same economic principle applying to oil applies to the ships carrying it.

Australia eventually pays for complexity

Every additional complication between an oilfield and an Australian service station has a cost.

Ship-to-ship transfers cost money.

Longer voyages cost money.

War-risk insurance costs money.

Due diligence costs money.

Tanker scarcity costs money.

Refining margins cost money.

Storage costs money.

None individually determines the Australian petrol price.

Together they contribute to the landed cost of fuel.

That is why events involving 45 tankers thousands of kilometres from Australia can eventually matter to an Australian trucking company, farmer or motorist.

Diesel remains particularly important

Diesel provides the clearest connection.

Australia moves enormous quantities of goods by road.

Agriculture depends heavily upon diesel.

Mining depends upon diesel.

Construction depends upon diesel.

Regional communities depend upon road freight.

Higher diesel costs therefore do not remain confined to the service station.

They move through supply chains.

A freight company eventually needs to recover its costs.

A farmer faces higher production costs.

A construction contractor faces higher equipment costs.

Those expenses can ultimately appear in prices paid by consumers.

Iran has discovered another form of leverage

For decades the great fear surrounding Hormuz was simple.

Iran might close it.

That remains possible.

But the events of 2026 are demonstrating something much more sophisticated.

Iran does not necessarily need to stop every ship.

It can influence:

which ships are considered safe to charter;

which ships insurers are willing to cover;

which vessels refiners are prepared to receive;

which ship-to-ship transfers companies are prepared to conduct;

and ultimately how expensive it becomes to move oil through the region.

That is economic leverage without a complete blockade.

But there is a limit to Iran's power

Iran cannot simply dictate terms without consequences.

It needs international trade itself.

Its economy depends heavily upon energy exports.

Aggressive interference with shipping encourages producers and customers to find alternatives.

Pipelines bypassing Hormuz become more valuable.

Alternative crude suppliers gain customers.

New LNG projects outside the Gulf become more attractive.

Shipowners redesign operations.

Countries diversify supply.

Every time Iran demonstrates the vulnerability of Hormuz, it simultaneously strengthens the commercial argument for making the world less dependent upon Hormuz.

That may become one of the great strategic ironies of the crisis.

What should we watch now?

The next indicators are increasingly clear.

Do more refiners announce that they will avoid the 45 vessels?

Do major shipowners refuse to charter them?

Do insurers impose additional restrictions?

Does Iran actually detain a blacklisted tanker?

Does a cargo get confiscated?

Do charter rates increase for vessels considered acceptable?

Does Iran remove ships from the blacklist after owners appeal?

And perhaps most importantly:

Does the emerging Iran-Oman navigation agreement supersede the blacklist — or coexist with it?

If a negotiated shipping framework eventually replaces unilateral Iranian rules, commercial confidence could recover.

If the blacklist remains an active enforcement tool, normalisation becomes much harder.

The Times View

Iran's blacklist initially looked like another threat in a conflict already overflowing with them.

Today it looks different.

Oil companies are beginning to change their behaviour.

That is the point at which a threat acquires economic substance.

Whether international companies believe Iran has the legal right to blacklist tankers is almost secondary to the immediate commercial calculation.

If they believe Tehran has the practical ability to detain a US$100 million ship or confiscate an enormously valuable cargo, prudent companies will take precautions.

Some now are.

That creates an uncomfortable reality.

Iran does not need the international community to formally recognise its authority over Hormuz for its rules to influence how Hormuz operates.

It needs companies to believe the consequences of ignoring those rules are greater than the cost of complying with them.

For Australia, the consequence again arrives through economics rather than geography.

Fewer commercially acceptable tankers.

More complicated transfers.

Higher risk.

More insurance.

More expensive logistics.

Eventually those costs can become part of the price of bringing fuel to Australia.

There is also a lesson for our assessment of the emerging Hormuz reopening.

Mine clearance matters.

Diplomatic agreements matter.

Oil prices matter.

But none tells us as much about real commercial confidence as what businesses actually do.

And today they have given us another piece of evidence.

Iran published the blacklist.

The oil companies are beginning to obey it.