Chinese Independent Refiners Curb Iranian Oil Imports as Refining Margins Shrink

China's independent refiners are curtailing purchases of Iranian oil due to squeezed refining margins, even as they remain the primary buyers despite intensifying U.S. sanctions pressure.

Trade sources report that these so-called "teapot" refiners in China, which handle the bulk of Iranian crude imports, continue buying despite renewed U.S. efforts to enforce sanctions. However, weak refining margins—the profit gap between crude costs and refined product prices—have limited their volumes, creating a natural brake on the flow of discounted Iranian oil. According to Asharq Al-Awsat, this dynamic persists amid Washington's campaign to close loopholes in the sanctions regime targeting financial channels linked to Tehran's oil exports.

The U.S. has escalated its strategy by sanctioning Chinese refineries, shipping entities, and the "shadow fleet" of vessels that obscure Iranian oil transport through tactics like turning off transponders and ship-to-ship transfers. As noted by Fox Business, experts like Gatestone Institute fellow Gordon Chang advocate broadening these measures to all involved refiners and vessels, warning that continued dealings could cut off access to the American financial system. Recent actions, including April sanctions on Iran's oil trade networks in China per the U.S. State Department, build on prior moves like September penalties against COSCO Shipping subsidiaries and Bank of Kunlun for evading restrictions.

China's role is pivotal: it buys about 90 percent of Iran's exported oil, generating tens of billions in revenue—roughly $31 billion in 2025 alone—that funds nearly half of Tehran's government budget, including military and regional activities, as detailed in a U.S.-China Economic and Security Review Commission fact sheet. Chinese banks, front companies, and intermediaries in places like Hong Kong launder payments and mislabel origins (often as Malaysian or Omani oil) to bypass scrutiny. This support helps Iran mitigate global isolation, but U.S. pressure has already prompted cutbacks, such as China National Petroleum Corp. scrapping a $5 billion Iranian gas project and imports dropping from 700,000 to just over 200,000 barrels per day.

The squeeze matters deeply for multiple players. Iran faces eroding funds for its destabilizing actions across the Middle East, while Chinese refiners grapple with economic viability amid volatile margins and sanction risks. U.S. officials aim to further isolate Tehran economically, potentially ratcheting up penalties if imports persist. For global markets, reduced Iranian flows could tighten supply, though China's dominance as Iran's top partner suggests any full halt remains unlikely without broader diplomatic shifts.

Looking ahead, tensions between Washington and Beijing could intensify if sanctions expand, testing China's balancing act between cheap oil access and avoiding secondary U.S. penalties. Chinese firms have shown sensitivity to pressure, scaling back in recent months, but independent refiners' resilience indicates the trade may endure at lower levels until margins or enforcement tip the balance further.