Tether CEO Paolo Ardoino has challenged a US Senate report alleging that the USDT stablecoin is used to bypass sanctions against Iran. Ardoino stated that Tether proactively freezes suspicious addresses, often acting before official designations by the US Treasury's OFAC or Israel's NBCTF.
According to Ardoino, since 2023, Tether has frozen assets on average four weeks ahead of official sanctions. The company claims that in 99% of cases, it blocks wallets before they are flagged by Chainalysis. Tether reports that these actions have led to a 94% reduction in Iran-linked stablecoin volumes.
The Senate report, published by Senator Richard Blumenthal on September 28, analyzed 846 crypto wallets linked to Iran, noting that 84% used USDT. The document alleges that Tether served as a tool for Iran's shadow banking system, citing a case where oil smugglers moved over $603 million in USDT between 2021 and 2025.
The Senate investigation also criticized Tether for slow response times in the past, noting that some sanctioned wallets remained active for weeks, with one instance resulting in $34.6 million being moved. The report calls for US regulators to hold stablecoin issuers accountable for anti-money laundering violations.
Tether maintains that it collaborates with over 340 law enforcement agencies across 70 countries and has frozen over $5 billion in assets to date. The company reported that it has blocked approximately $550 million in USDT associated with Iran-linked addresses since the beginning of 2026.
