How Sanctions Shape Iran’s Oil Sales and the Global Oil Market

How did Iran oil sanctions begin in 2012?

Iran oil sanctions in their current form date from late 2011 and 2012, when the United States and the European Union (EU) added measures aimed directly at Iran's oil sales to earlier limits on investment. US measures adopted at the end of 2011 targeted transactions with the Central Bank of Iran ^[2,3]. On 23 January 2012 EU foreign ministers agreed an embargo on Iranian oil. New contracts were banned immediately and existing ones could run until 1 July ^[1]. The EU also barred European protection and indemnity (P&I) clubs from insuring tankers carrying Iranian oil, a step that affected refiners in South Korea and India ^[2].

The effect on volumes was large. Iran's crude and lease condensate exports fell from about 2.5 million barrels per day (mb/d) in 2011 to about 1.5 mb/d in 2012, a 39% decline and the lowest level since 1986. Net oil export revenue fell from $95 billion to $69 billion ^[2]. In August 2012 Iran's crude output fell below Iraq's for the first time since 1989 ^[2].

The customer mix changed with it. In 2011 the EU had been the second-largest regional buyer at nearly 600,000 barrels per day (b/d), alongside China at 550,000 b/d, India at 320,000 b/d, Japan at 315,000 b/d and South Korea at 250,000 b/d. Almost all buyers then reduced or halted purchases. By 2013 the main importers were China, India, Japan, South Korea, Turkey, the United Arab Emirates and Syria. Exports were just below 1.3 mb/d in 2013 and averaged 1.4 mb/d in 2014 ^[3]. The wider market absorbed the loss: world oil supply rose by about 1.8 mb/d in 2012 ^[2].

What changed under the JCPOA (2016–2018)?

The 2015 nuclear agreement, the Joint Comprehensive Plan of Action (JCPOA), was endorsed by UN Security Council Resolution 2231, which lifted earlier UN sanctions ^[10]. Implementation Day came on 16 January 2016, when the International Atomic Energy Agency verified that Iran had completed the key physical steps ^[4]. The EU lifted its nuclear-related measures, including those on oil, at the same stage ^[10].

Iran was ready to sell quickly. It held between 30 and 50 million barrels of oil in tankers offshore, mostly condensate, and the US Energy Information Administration (EIA) expected the first rise in exports to come from storage ^[4]. Crude output, which averaged 2.8 mb/d in 2015 ^[4], exceeded 3.8 mb/d in 2017 and passed its pre-2012 level ^[5]. Exports of crude and condensate peaked at about 2.7 mb/d in June 2018 ^[6].

Buyers diversified again. Several European countries resumed purchases in 2016–2017. In 2017 China took 25% of Iran's crude and condensate exports, Europe 20%, India 17%, South Korea 13% and Turkey 9% ^[5].

How did the 2018 reimposition affect Iranian oil exports?

In May 2018 the United States announced its withdrawal from the JCPOA and the reinstatement of sanctions. The first wind-down period ended on 6 August, and full energy-sector sanctions returned on 4 November 2018 ^[6]. Buyers began reducing purchases before the deadline. France imported nothing after June and South Korea stopped in July. Exports fell to 1.9 mb/d in September. China's intake dropped from 644,000 b/d in the first half to 441,000 b/d, while India's edged up to 576,000 b/d ^[6].

Eight large importers then received six-month exemptions. When these expired in May 2019, Iran's crude and condensate exports fell below 500,000 b/d for the rest of 2019 and most of 2020 ^[5].

How did China become the main buyer of Iranian oil?

After that low point, Iranian crude flows rebuilt to roughly 1.5–2 mb/d by 2024–25, according to Vortexa ^[11]. The buyer base narrowed sharply. Kpler data cited by Reuters show China bought an average of 1.4 mb/d in 2025 and took more than 80% of Iran's shipped oil. Independent refiners in Shandong province, which account for about a fifth of China's refining capacity, were the main buyers. Beijing rejects unilateral sanctions ^[12].

US policy tightened again in February 2025. A presidential memorandum directed a campaign aimed at "driving Iran's oil exports to zero" and asked the Treasury to issue guidance for shipping, insurance and port operators ^[9]. Later US actions covered vessels, intermediaries, Chinese independent refiners and terminals ^[11].

UN measures returned in September 2025. France, Germany and the United Kingdom triggered the JCPOA "snapback" mechanism on 28 August, and UN sanctions were reinstated on 27 September. The restored UN measures centre on nuclear, missile and arms restrictions and asset freezes. On 29 September the EU reimposed its nuclear-related measures, which include bans on the import, purchase and transport of Iranian crude oil, petroleum products, natural gas and petrochemicals ^[10].

2026: from sanctions to a blockade

The war that began on 28 February 2026 shifted the main constraint from sanctions to physical access. The United States imposed a naval blockade on Iranian ports and shipping from 13 April ^[11]. After a period of easing, it was reimposed on 13 July, when a deal to halt the war broke down ^[12]. Vortexa data show Iranian crude loadings fell to about 210,000 b/d in August, the lowest since 2020, from roughly 2 mb/d earlier in the year ^[11].

Oil already at sea cushioned the fall for a time. Reuters reported in August that Iranian crude in floating storage outside the blockade zone had fallen to about 80 million barrels, from about 105 million before the blockade was reinstated ^[12]. Kpler estimated that Iranian floating inventories available for delivery to China had fallen below 1 million barrels by 5 October ^[14]. Sanctions policy has also continued to develop. In August the US Treasury Secretary said further sanctions would follow ^[12]. On 18 September the President signed the Sanctioning Russia and Iran Act of 2026. Apart from extending the Iran Sanctions Act of 1996 through 2031, its provisions concern Russia ^[13].

How do sanctions affect oil prices, freight and other suppliers?

Prices. In October 2018 the EIA said the sanctions, Iran's response and the reaction of other producers posed significant uncertainty to its forecasts. A mismatch between other producers' response and the volumes actually removed would likely increase price volatility. It expected OPEC spare capacity to fall to 1.6 mb/d in 2018 and 1.3 mb/d in 2019, below the 2008–2017 average of 2.3 mb/d. Brent averaged $79/bbl in September 2018 ^[7]. When OPEC and its partners agreed on 7 December 2018 to cut output by 1.2 mb/d from January 2019, Iran was exempted because of US sanctions. Brent rose 5.2% to $63.17/bbl on the news ^[8]. Prices for Iranian grades rose as offers to China declined. In August 2026 Iranian Light was offered to China at about $3/bbl below ICE Brent, the same as a month earlier, and some cargoes were offered at a premium of about $2/bbl ^[12].

Other suppliers. Vortexa sees Russian and Middle Eastern grades as the most likely substitutes for Chinese buyers, because shorter voyages matter when freight is expensive. West African and South American crude is less likely to be the first choice ^[11]. China has turned to Russian crude. Premiums for Russian crude reached as much as $13/bbl over regional benchmarks for October cargoes, before falling to $1–2/bbl for December ^[15]. Our review of Russian oil exports and sanctions covers that market in detail. Beijing has also told its largest oil and gas producers to expand domestic capacity ^[14].

Freight. Goldman Sachs estimates that the global average crude freight rate has risen above $20/bbl. It attributes $2/bbl of the rise to the blockage of the Iranian fleet, which increases demand for tankers that are not subject to sanctions ^[16].

What could easing or tightening of Iran sanctions mean?

Analysts describe two broad paths.

• Continued restrictions. Vortexa expects loadings to remain exceptionally low while floating storage near buyers keeps falling, with growing pressure on Iran's production capacity. Partial leakage could restore some trade, but unevenly ^[11].
• A durable reopening. Iran still has an established tanker network and a large Chinese buyer base. Crude already positioned for export could move quickly, but sustained volumes would depend on tankers returning to reload ^[11]. In 2016 the EIA likewise expected the first increase to come from storage ^[4]. The EIA estimated in 2021 that output could reach its 3.8 mb/d capacity within about 18 months of oil sanctions being lifted ^[5].

For the market, the key signals are Iranian loadings, Chinese purchases of substitute grades, and freight rates for tankers outside the sanctions system. Iran's capacity remains a large potential source of supply, and policy decisions will continue to determine how much of it reaches buyers.

Alupetra follows Iranian supply as part of its market analysis and does not deal with sanctioned persons, entities or vessels.