US Sanctions Turkish Bank Accused of Providing Financial Lifeline to Iran

The United States has imposed sanctions on a Turkish investment bank and two of its subsidiaries, accusing the institutions of helping Iran maintain access to international financial channels and facilitating transactions connected to the Islamic Revolutionary Guard Corps’ Quds Force (IRGC-QF).

The action, announced on September 4, represents a significant escalation in Washington’s campaign to restrict Iran’s access to the global financial system. The measures target Istanbul-based Golden Global Yatirim Bankasi Anonim Sirketi, together with Golden Global Varlik Kiralama Anonim Sirketi and Golden Global Portfoy Yonetimi Anonim Sirketi. All three entities were designated under the US Iran sanctions framework and added to the Specially Designated Nationals and Blocked Persons List.

The US Treasury alleges that Golden Global Bank provided correspondent banking services to Iranian financial institutions and facilitated transactions involving accounts controlled by the IRGC-QF and associated networks. Authorities said the bank played a role in enabling Iranian oil revenues to move from China through Türkiye, where the funds could subsequently be converted into cash and gold.

The allegations place particular emphasis on the bank's role as a bridge between Iran and the international financial system. Despite Iran being subject to extensive US sanctions, Iranian entities have continued to generate revenue through international trade and then rely on financial intermediaries, exchange houses, front companies and correspondent banking relationships to move funds across borders.

According to the US authorities, Golden Global Bank was established or used to support a network capable of transferring Iranian oil proceeds from China into Türkiye. The funds could then be converted into alternative stores of value, including physical cash and gold, creating additional layers between the underlying Iranian revenue and the financial institutions through which it originated.

The Treasury also linked Golden Global Bank to transactions involving Turkish businessman Sitki Ayan and companies associated with him. Ayan's network was previously sanctioned over alleged involvement in the movement of hundreds of millions of dollars connected to oil sales benefiting the IRGC-QF.

The designation has consequences extending beyond the three entities directly named. Property and interests in property belonging to designated persons that are located in the United States or within the possession or control of US persons are blocked. Transactions involving blocked persons are generally prohibited unless authorised or otherwise exempted.

The US sanctions regime also applies through the so-called 50 Percent Rule, meaning that entities owned, directly or indirectly, individually or collectively, by one or more blocked persons at a level of 50% or more are generally treated as blocked even when they have not been separately named on the sanctions list.

The broader significance for international financial institutions may be even greater. The Treasury has warned that foreign financial institutions involved in significant transactions for sanctioned Iranian parties can face secondary sanctions exposure, including restrictions affecting their ability to maintain correspondent or payable-through accounts in the United States.

This creates a substantial compliance risk for banks outside the United States. A financial institution does not necessarily need to be a US entity to face consequences from facilitating transactions connected to sanctioned Iranian parties. Access to the US dollar clearing system and relationships with US correspondent banks can become important points of vulnerability.

The latest action forms part of a wider US initiative known as Operation Economic Outcast, launched in August with the objective of intensifying pressure on Iran's international financial and commercial networks. The campaign is designed to identify the channels through which Iran generates revenue, circumvents sanctions and transfers money internationally.

The strategy is particularly focused on the shadow banking structures that have developed around Iran's heavily sanctioned economy. These networks can involve banks, exchange houses, trading companies, offshore entities, intermediaries and other businesses that provide financial or commercial services capable of moving funds while obscuring their Iranian origin or ultimate destination.

The designation of a bank in Türkiye is particularly notable because Türkiye is a major regional financial and commercial hub. It also illustrates the increasing geographic reach of US sanctions enforcement. International banks operating in countries that maintain legitimate commercial relationships with Iran may find themselves having to distinguish between permissible trade and transactions that could expose them to US sanctions.

The latest action is also notable because Golden Global is relatively small compared with the major international banks that dominate cross-border finance. The bank reportedly held approximately 25 billion Turkish lira in assets in 2025, equivalent to slightly more than $500 million at recent exchange rates. Nevertheless, its alleged position within an Iranian financial network was sufficient to attract US enforcement attention.

Golden Global has rejected the allegations and stated that it complies with Turkish and international banking and compliance requirements. The bank has also disputed having direct or indirect dealings with the individuals and entities identified in the US sanctions action and indicated that it intends to pursue legal remedies.

For compliance departments, the case demonstrates why sanctions risk cannot be assessed solely by checking the names of direct customers against sanctions lists. A financial institution can face significant exposure through the broader network surrounding a transaction.

Correspondent banking relationships are particularly sensitive. Banks providing correspondent services to foreign financial institutions must understand not only the identity of the respondent bank but also the types of customers, jurisdictions, products and transactions that are likely to flow through the relationship.

Transactions involving countries subject to comprehensive sanctions require enhanced scrutiny, particularly where funds originate from sectors such as oil and petrochemicals. Complex payment chains involving multiple jurisdictions can make it difficult to determine the true source of funds unless banks examine the underlying commercial purpose and counterparties rather than relying exclusively on payment messages.

The use of China, Türkiye and other jurisdictions in the alleged movement of Iranian oil proceeds also demonstrates the importance of geographic risk assessments. A transaction may not contain an obvious Iranian counterparty even when its economic substance is connected to Iran. Funds can pass through multiple companies, banks and jurisdictions before reaching their final destination.

The alleged conversion of funds into cash and gold introduces another significant financial crime risk. Precious metals and cash can be used to reduce transparency and create additional distance between illicit proceeds and the financial transactions that generated them. Institutions dealing with businesses involved in commodities, precious metals, foreign exchange or cross-border payments therefore need to understand the customer's expected transaction profile and the economic rationale for unusually complex flows.

Beneficial ownership and control remain equally important. Sanctions evasion networks frequently rely on layers of companies and intermediaries, meaning that identifying the immediate customer may not be sufficient. Financial institutions need to establish who ultimately owns or controls counterparties and whether those individuals or entities have connections to sanctioned persons or networks.

The action also reinforces the importance of transaction monitoring capable of identifying patterns rather than isolated transactions. A single payment may appear commercially plausible, while a series of payments involving Iranian counterparties, offshore companies, commodity traders, exchange houses, unusual jurisdictions and multiple intermediaries may reveal a substantially different risk profile.

Financial institutions should therefore consider whether their sanctions controls are capable of detecting indirect exposure to Iranian financial networks. Relevant indicators can include unusual payment routes, unexplained involvement of intermediary banks, inconsistent trade documentation, transactions involving high-risk commodities, rapid movement of funds between jurisdictions and counterparties whose ownership structures are difficult to establish.

Another important issue is the distinction between sanctions screening and sanctions risk management. Screening is essential, but it cannot substitute for broader customer due diligence. A transaction can involve parties whose names do not appear on a sanctions list while still presenting significant sanctions-evasion indicators.

The Golden Global case illustrates how enforcement authorities increasingly focus on the financial infrastructure supporting sanctioned regimes rather than limiting action to governments, state-owned enterprises or traditionally designated individuals. Banks and financial intermediaries that provide the infrastructure through which money moves can themselves become targets.

The designation also demonstrates the potential consequences of operating within a financial ecosystem where US dollar clearing remains important. Being outside the United States does not necessarily shield an institution from US sanctions exposure. Foreign banks may depend on US correspondent relationships, dollar clearing or access to international counterparties that themselves maintain US connections.

For compliance officers, the development should therefore be viewed as a warning about correspondent banking, sanctions circumvention and third-country exposure. Institutions that maintain relationships with banks in Türkiye, the Gulf, Asia or other jurisdictions conducting legitimate trade with Iran may need to reassess their exposure to Iranian financial networks and the adequacy of their existing controls.

The US action comes amid a broader intensification of financial pressure on Iran. In recent weeks, Washington has signalled that financial institutions and other businesses facilitating Iranian transactions may face increased scrutiny and sanctions exposure. The approach is intended to make access to international financial infrastructure increasingly difficult for entities supporting Iran's revenue-generating and sanctions-evasion activities.

The immediate impact of the Golden Global designation will be felt most directly by the sanctioned entities and their counterparties. However, the wider compliance implications are likely to extend across the international banking sector. Financial institutions will need to assess whether they have any direct or indirect exposure to the designated entities, review correspondent relationships and identify transactions that may involve blocked persons or entities owned or controlled by them.

The case ultimately highlights a broader transformation in sanctions enforcement. Authorities are increasingly targeting the infrastructure that allows sanctioned economies to continue operating rather than focusing solely on the final recipient of funds. Banks, payment institutions, investment firms, exchange houses and other financial intermediaries can therefore become critical enforcement targets when they provide access to international markets.

As sanctions regimes become more sophisticated, financial institutions will need to move beyond simple name matching and adopt a more comprehensive approach combining customer due diligence, beneficial ownership analysis, transaction monitoring, geographic risk assessment, correspondent banking controls and continuous sanctions screening. For institutions operating in or maintaining financial links with Türkiye and other regional financial hubs, the latest action is another indication that indirect exposure to Iranian financial activity is becoming an increasingly significant compliance risk.

By fLEXI tEAM