Tether reported freezing nearly $550 million in USDT connected to Iran during 2026, while Senate investigators identified potential compliance gaps that may have allowed tens of millions of dollars to transfer before addresses were blacklisted.
A preliminary report released September 28 by Democratic minority staff of the Senate Permanent Subcommittee on Investigations examined 846 crypto wallets sanctioned or targeted by U.S. or Israeli authorities for their Iran connections. The report found that 84% of these wallets transacted exclusively or nearly exclusively in USDT, a stablecoin designed to track the U.S. dollar.
Sen. Richard Blumenthal, the Connecticut Democrat and ranking member of the subcommittee, referred the findings to the Treasury and Justice departments, requesting an investigation into Tether's anti-money laundering and sanctions compliance. The referrals do not establish that Tether violated federal law or that either department has opened a new case.
Timing Concerns
Democratic investigators focused on the timing of when Tether blacklisted addresses. The report examined 39 wallets identified by Israel's National Bureau for Counter Terror Financing in June 2023 as connected to an individual later sanctioned by the U.S. Treasury for providing financial services to Hezbollah. According to Senate staff, five addresses were blacklisted immediately, but 34 remained unfrozen until March 2024. Investigators calculated that more than $34.6 million in USDT moved from those wallets after the Israeli seizure notice was published and before the remaining addresses were frozen.
Tether's Response
Tether's September 28 statement highlighted enforcement actions from 2026. On April 23, the company said it froze more than $344 million in USDT across two addresses after receiving information from the Office of Foreign Assets Control and U.S. law enforcement. The following day, OFAC added those blockchain addresses to the Central Bank of Iran's sanctions entry. In July, Tether froze more than $130 million in USDT across four wallets as Treasury expanded the Central Bank of Iran's listed blockchain addresses.
CEO Paolo Ardoino stated that Tether acts when authorities provide credible information and argued that public blockchains provide investigators with visibility into fund movements that cash does not.
Tether's statement did not directly address the report's analysis of the 846 wallets or the $34.6 million example that investigators said moved before addresses were frozen. The Senate report noted that Tether acknowledged receiving an information request from the subcommittee on June 4 but had not responded as of the report's publication.
Broader Context
A separate U.S. forfeiture case is seeking approximately $61 million in cryptocurrency allegedly tied to black-market Iranian oil sales. Federal prosecutors said the wider network moved more than $1.5 billion in proceeds and alleged that some funds were intended to benefit Iran's government and military.
The cases illustrate both the capabilities and limitations of issuer-controlled stablecoins. Authorities can immobilize large balances once they identify addresses, but delays in blacklisting can allow funds to transfer. Whether the delays identified by Senate investigators represent isolated enforcement gaps or broader compliance failures remains under federal review.
