An Iranian engineering firm ordered 150,000 circuit boards and sensors from a Chinese supplier. The price was $650,000. The invoice said the payment should be routed through a clearing partner in New York.

Iran is locked out of the American financial system. Iranian banks cannot hold American accounts. So why did the paperwork point at New York?

Because for a payment in US dollars, there is nowhere else to point. That is the part almost nobody has had explained to them, and it is the whole story. The invoice was seen by The Wall Street Journal, which reported it last week. Whether the money ever moved is unclear.

About nine billion dollars found its way through in one year.

Money does not actually go anywhere

Start with the bit everyone gets wrong. When an Australian business pays an overseas supplier in US dollars, nothing physically leaves the country. No cash is loaded onto a plane. A bank in America subtracts a number from one account and adds it to another. That is the entire event.

Think of the US dollar as a scoreboard. Every dollar that exists is a line on that scoreboard, and the scoreboard is kept in the United States. Change the lines and the money has moved. There is no other way to move a dollar, anywhere, ever.

Your bank in Melbourne has no branch on Wall Street. So it keeps an account at an American bank instead, and when you pay in dollars it asks that American partner to make the change for you. The account is called a correspondent account. The arrangement is more than a century old and it is the reason cross-border payment works at all.

It also hands Washington a lever. If every dollar payment on earth is finished off inside an American bank, America can watch them and switch any of them off. That is what a sanction is in practice. It is a line on the scoreboard that stops updating.

How Iran gets on the scoreboard

Iran still needs dollars. It buys restricted technology, it supports allies, and some trade only settles in dollars. So it built a way around the front door. The route runs in five steps, and it is simpler than most people expect.

Step one. Iran cannot ask directly. Its banks are sanctioned. Bank Tejarat, the Iranian bank named on that invoice, is one of them. No American bank will hold an account for it, and no foreign bank wants to be caught passing on its instructions.

Step two. So the request comes from somewhere that looks ordinary. Iran uses shell companies and currency exchange houses in places like Dubai and Hong Kong. Local names, local addresses, a plausible line of business, and no visible link to Tehran. On the same day it acted against Banque Misr, the Treasury also named a Hong Kong company, Kameng Trading, as a front laundering money for an Iranian exchange house.

Step three. Those companies bank at a normal bank. They open accounts at a foreign bank that already holds a correspondent account at an American one. That is the entire trick. On 28 August the Treasury's financial crimes unit named the UAE branches of Banque Misr, Egypt's second largest bank, as one such route. It said those branches processed about $1.8 billion for 103 companies potentially tied to Iran's shadow banking networks between January 2024 and June 2026.

Step four. The American bank sees a customer it knows. It sees a foreign bank it deals with every day, and an instruction carrying a company name with nothing wrong on the face of it. Tehran is two companies further back and appears nowhere on the paperwork. The bank updates the scoreboard. Banque Misr lists JPMorgan Chase and Citigroup on its own website as correspondent banks. Both declined to comment on the Treasury action.

Step five. The goods ship. Circuit boards and sensors of the kind on that invoice go into car manufacturing. They also go into weapons and drones, which is why Iran wants them and why the payment needed a disguise in the first place.

Why nobody just switches it off

Washington could tighten this tomorrow. It moves carefully instead, and the reporting gives three reasons.

Reason one. Cutting a bank off has killed banks before. Losing dollar access has destroyed foreign institutions outright and taken a piece of the local economy with them. Even in this case the Treasury proposed the rule and opened a thirty day comment window rather than pulling the plug on the day. Banque Misr said it was reviewing the notice.

Reason two. Leaning on American banks makes them quit. Correspondent banking earns fees and deposits, and it is also where the compliance burden lands. Push too hard and American banks withdraw the service from entire regions. Ordinary businesses in those regions then discover they cannot get paid, for reasons that have nothing to do with them.

Reason three. Squeezing the dollar creates a market for something else. Iran already prefers Chinese yuan and cryptocurrency wherever it can use them. Alex Zerden, a former Treasury official, has said that using these tools "creates incentives for alternatives". Here is why that matters. Every payment that leaves the dollar system is a payment America can no longer see, so enforcing hard today buys blindness tomorrow.

What this has to do with your business

The Australian read that follows is inference. It comes from how the system works rather than from anything the reporting states about Australia. Australian businesses settle US dollar payments through the same correspondent chain, so the same machinery is looking at them.

Find out who clears your foreign currency payments. Ask your bank which American institution settles your US dollar transfers. You are depending on a relationship you have never seen and cannot influence. If it changes, your payments slow down and you will want to know why. One email answers it.

Search your own business the way a compliance officer would. The Treasury's published warning signs for banks include opaque company ownership and a firm with no online presence at all. A thin digital footprint now reads as a risk signal inside a bank's system. Your website is doing a job you never hired it for, and so is your supplier's.

Get your intermediaries' ownership in writing. If your supply chain runs through an agent in the UAE or Hong Kong, ask who owns the company you are paying and keep the answer on file. Enforcement sweeps are aimed at somebody else and catch whoever is standing nearby.

The plumbing decides who gets paid. Find out where yours runs.