For years, China has been buying discounted Iranian oil in bulk, and the U.S. sanctions on Tehran have barely put a dent in that trade, analysts said, thanks to a shadow supply chain of transshipment and a yuan-denominated payment system that bypasses the U.S. dollar.

Chinese customs have not shown any oil shipped from Iran since July 2022. Ship tracking data from analytics firm Kpler, however, indicated China’s Iranian crude imports have continued to rise since then, nearly doubling to 17.8 million barrels per day (mbd) in 2024 from the 2022 level.

In the first five months of this year, those imports have remained at an elevated level of 6.8 mbd, little changed from the same period in 2024.

China is still the largest consumer of Iranian crude by far. The U.S. Energy Information Administration suggested in a report in May that nearly 90% of Iran’s crude oil and condensate exports continued to flow to China.

Iran has faced some of the broadest sanctions the U.S. has imposed on any country as Washington sought to choke the regime’s main source of revenue that was used to fund its nuclear program and militias such as Hamas and Hezbollah. The Trump administration has been actively imposing fresh sanctions on tankers involved in facilitating Iranian crude to China.