Treasury Warns Banks Over China Refineries Buying Iranian Oil

U.S. sanctions pressure is moving from tankers to the payment channels behind Tehran's oil trade.

WASHINGTON, D.C. - The Treasury Department warned financial institutions that Chinese independent oil refineries buying Iranian crude could expose banks and foreign counterparties to U.S. sanctions, widening Washington's pressure campaign from ships and brokers to the financing channels behind Tehran's oil revenue.

The American stake is direct. Treasury says Iranian oil revenue supports the regime's weapons programs and military, while OFAC is putting U.S. financial institutions, correspondent banks, and non-U.S. firms on notice that dollar-linked transactions can become sanctions targets.

The Story So Far

Treasury said April 28 that OFAC issued an Iran-related alert titled "Sanctions Risk of Dealing with Teapot Oil Refineries," published one Iran-related frequently asked question, and updated the Specially Designated Nationals and Blocked Persons List.

The alert focuses on independent Chinese oil refineries, often called teapot refineries, primarily in Shandong Province. Treasury said those refineries have played a major role in buying and processing Iranian crude.

According to Treasury, China buys about 90 percent of Iran's oil exports, and teapot refineries account for most of those imports. Treasury said the revenue "ultimately benefits the Iranian regime, its weapons programs, and its military."

The April 28 warning followed an April 24 Treasury action against China-based independent teapot refinery Hengli Petrochemical Dalian Refinery Co., Ltd. and roughly 40 shipping firms and vessels. Treasury said that action was taken under Executive Order 13902 and in furtherance of the administration's Iran pressure campaign.

What's Happening Now

The April 28 alert tells financial institutions to watch for sanctions exposure tied to transactions involving Chinese teapot refineries. Treasury said some refineries have used the U.S. financial system to conduct dollar-denominated transactions and procure U.S. goods.

That is the enforcement mechanism. Even when crude moves from Iran to China through foreign companies, the use of dollar payments, correspondent banking, U.S. goods, or blocked entities can create a U.S. sanctions problem.

Photo by Zhangmoon618, via Wikimedia Commons (CC BY-SA 4.0)

Treasury urged financial institutions to use risk-based controls and enhanced due diligence for transactions involving China-based refineries, especially in Shandong Province. The department also told institutions to communicate sanctions-compliance expectations to correspondent banks.

Treasury said evasion tactics in the trade include front companies in Asia and the United Arab Emirates, intermediary brokers, shadow-fleet shipping, ship-to-ship transfers, falsified documentation, and vessel identity manipulation.

The Conservative View

The administration's case is that sanctions enforcement can cut into Iran's oil revenue without direct military action. Treasury Secretary Scott Bessent said April 24 that covert trade and finance tied to Iranian petroleum carry sanctions risk.

"Any person or vessel facilitating these flows, through covert trade and finance, risks exposure to U.S. sanctions," Bessent said in Treasury's April 24 announcement.

That argument treats banks, shipping firms, brokers, insurers, and refiners as pressure points. If financial institutions cut off the payment channels around Iranian-origin oil, Treasury's strategy is to make the trade harder, more expensive, and riskier for counterparties.

Supporters of maximum pressure also point to the weapons and military funding claim. Treasury's April 28 statement ties refinery purchases to revenue for Iran's regime, weapons programs, and military, which places the sanctions alert inside the broader U.S. effort to protect American troops, allies, and shipping from Iranian-backed threats.

The Progressive View

Critics of broad sanctions often argue that pressure campaigns can expand quickly and produce costs beyond the targeted officials or companies. The April 28 alert shows how a sanctions program can move from named vessels and entities into banks, correspondent relationships, trade finance, and ordinary compliance systems.

The concern is the compliance drag. A bank trying to avoid sanctions risk may restrict relationships with customers that are not themselves designated but have indirect links to Chinese refinery networks, commodity brokers, or shipping chains. That can widen the practical effect of the policy beyond the entities named by OFAC.

Civil-liberties and humanitarian critiques of sanctions also tend to focus on whether financial pressure changes government behavior or hardens the target country's workarounds. The brief for this article did not include a direct progressive statement on the April 28 alert, so this section is limited to the policy tradeoff shown by Treasury's own enforcement design: broader pressure can increase U.S. bargaining power, but it can also increase compliance costs and indirect economic disruption.

Other Perspectives

For U.S. financial institutions, the alert is a compliance warning. Banks must evaluate dollar transactions, correspondent relationships, customers tied to China-based refineries, and payments linked to shipping or brokerage networks that could touch Iranian-origin crude.

For Chinese teapot refineries, Treasury's allegation is that the sector accounts for most of China's Iranian oil imports and has used fronts, brokers, and shadow-fleet logistics. The brief did not identify a direct official response from China or any named refinery to the April 28 alert.

For Iran and the IRGC, OFAC's FAQ 1249 adds a separate warning tied to the Strait of Hormuz. OFAC said payments to Iran's government or the IRGC for safe passage through the strait would not be authorized for U.S. persons, including U.S. financial institutions and U.S.-owned or controlled foreign entities.

Economic Implications

The economic mechanism is compliance friction. Treasury's warning pushes banks and counterparties to screen not only names on sanctions lists, but also refinery geography, cargo origin, shipping behavior, trade documents, counterparties, and indirect links to Shandong-based refinery networks.

Photo by Martian-2007, via Wikimedia Commons (CC BY-SA 4.0)

For Americans, the risk channel runs through energy security, the dollar system, and shipping exposure in the Middle East. If enforcement raises costs for shadow-fleet shipping, commodity brokerage, refinery financing, and insurance, Treasury's goal is to reduce Iran's oil revenue. The tradeoff is that rerouted cargoes and higher compliance costs can add friction to oil logistics and financing.

The Strait of Hormuz warning is separate but related. OFAC said U.S. persons are not authorized to make safe-passage payments to Iran or the IRGC, directly or indirectly. That means a shipping or financial arrangement designed to keep cargo moving through a high-risk waterway can become a sanctions issue if it routes money to the Iranian government or the IRGC.

By the Numbers

• 90 percent - China's approximate share of Iran's oil exports, according to Treasury.
• More than 1,000 - Iran-related persons, vessels, and aircraft OFAC has sanctioned since February 2025, according to Treasury.
• Roughly 40 - Shipping firms and vessels included in Treasury's April 24 action with Hengli Petrochemical Dalian Refinery Co., Ltd., according to Treasury.
• 1 - New Iran-related FAQ, FAQ 1249, issued by OFAC on April 28.
• 2 - Main risk channels named in the brief: dollar-denominated transactions and procurement of U.S. goods.

What People Are Saying

"China purchases approximately 90 percent of Iran's oil exports, with teapot refineries accounting for the majority of these imports. This revenue ultimately benefits the Iranian regime, its weapons programs, and its military."

U.S. Treasury Department, April 28

"Some Chinese teapot refineries have used the U.S. financial system to conduct dollar-denominated transactions and procure U.S. goods."

U.S. Treasury Department, April 28

"The alert also highlights common evasion tactics used in this trade, including the use of front companies in Asia and the United Arab Emirates, intermediary brokers, and a 'shadow fleet' employing deceptive shipping practices such as ship-to-ship transfers, falsified documentation, and vessel identity manipulation."

U.S. Treasury Department, April 28

"Payments to the Government of Iran or the Islamic Revolutionary Guard Corps (IRGC), directly or indirectly, for safe passage through the Strait of Hormuz would not be authorized for U.S. persons, including U.S. financial institutions, or for U.S.-owned or -controlled foreign entities."

OFAC FAQ 1249

"Since February 2025, OFAC has sanctioned over 1,000 Iran-related persons, vessels, and aircraft as part of this campaign."

U.S. Treasury Department, April 24

"Any person or vessel facilitating these flows, through covert trade and finance, risks exposure to U.S. sanctions."

Treasury Secretary Scott Bessent, April 24

The Big Picture

The April 28 alert signals that Treasury is watching the financial infrastructure around Iranian oil, not only the ships moving it. The next test is whether banks restrict trade-finance exposure, correspondent relationships, or customer activity tied to Shandong-based refineries and Iranian-origin cargoes.

The unanswered questions are also practical. OFAC could name more Chinese independent refineries, target foreign financial institutions, or move against insurers, brokers, and traders. China, Iran, or affected companies could also issue formal responses.

For Americans, the issue is whether sanctions enforcement reduces money available to Iran's military and weapons programs without increasing energy-market instability or drawing U.S. institutions into a wider compliance fight. Treasury's alert makes clear that the next stage of the pressure campaign will run through banks as much as tankers.