The snapback of UN sanctions on Iran took effect on September 27, 2025, after the E3 (France, Germany, UK) triggered the mechanism under UN Security Council Resolution 2231 and the Security Council failed to extend sanctions relief. Please see our previous Alert on the snapback process and what this could mean for global businesses.

The EU and UK have begun to re-impose on Iran their respective sanctions pre-dating the Joint Comprehensive Plan of Action (JCPOA).

• EU Actions: On September 29, the EU announced the re-imposition of a broad array of restrictive measures on Iran:
  • Council Regulation 2025/1975: Amends Council Regulation 267/2012, restoring sectoral and trade sanctions, including:
    • bans on the supply to Iran of nuclear and ballistic missile-related items, gold, precious metals, diamonds, certain software, and key equipment for the energy sector;
    • prohibitions on the import, purchase and transport of crude oil, gas, petrochemical and petroleum products and related services;
    • transport restrictions, such as prohibitions on providing services to Iranian vessels/aircraft suspected of carrying prohibited goods; and
    • various banking and financial restrictions, including with respect to the transfer of funds to and from Iran and prohibitions on new Iranian banking relationships.
  • Council Implementing Regulation (EU) 2025/1980: Reinstates previous EU asset freezes, including on the Central Bank of Iran, Bank Mellat, Bank Melli, and others.
  • Council Implementing Regulation 2025/1982: Reintroduces previous UN asset freezing sanctions on individuals and entities.

Certain prohibitions are subject to time-bound wind-down provisions for pre-existing contracts.

The EU’s sanctions measures mirror the scope of EU sanctions on Iran prior to the 2013 Joint Plan of Action (an interim agreement between Iran and the P5, plus Germany, pursuant to which the EU suspended certain measures before its more fulsome lifting of sanctions post-JCPOA), and notably go further than the UN sanctions alone, including restrictions on energy, transport, and finance.

• UK Actions: In parallel,  the UK has:
  • Passed regulations to amend the UK’s Iran nuclear sanctions regime (which, post-Brexit, is autonomous from the EU) to reflect the reintroduction of UN sanctions.  In particular, the amending regulations:
    • re-introduce references to UNSC Resolutions 1737, 1747, 1803 and 1929 (and the UK’s obligations under the same);
    • make technical amendments to ensure all lists of controlled items reflect UN Security Council control lists;
    • amend the asset freezing criteria to ensure there are grounds under UK law to designate UNSC sanctioned persons and entities; and
    • introduce an exemption enabling payments in respect of certain HMT sovereign debt products (in line with other sanctions regimes).
  • Updated its Sanctions List, adding 192 individuals and entities that are now subject to asset freezing sanctions.  These sanctioned individuals and entities include major Iranian banks, energy and petrochemical firms, government ministries, and companies linked to nuclear and missile proliferation.
  • Issued four new General Licenses (GLs) to support UK businesses:
    • GL INT/2025/7363752 which permits continued operation of the Shah Deniz Project.
    • Three GLs for wind-down of transactions involving Iran Insurance Company and the National Iranian Oil Company (NIOC) International Affairs Ltd, specified Iranian banks (operating worldwide), and specified UK-based Iranian banks.
    • OFSI also released FAQ 168 clarifying that previous specific licenses issued under the UN regime prior to 2015 are no longer valid, and new license applications must be submitted as needed.

The UK’s amendments to date are fairly contained since the UK (and EU) had maintained measures consistent with many of the UN sanctions on Iran. The UK has stated that it intends to bring in legislation to impose further sectoral measures, targeting “finance, energy, shipping, software, and other significant industries which are advancing Iranian nuclear escalation.”