Tether says Iran-linked USDT freezes reached $550 million as Senate scrutiny grows

Tether says actions involving its USDT stablecoin froze approximately $550 million across wallets that U.S. authorities connected to Iran's central bank and sanctions networks during 2026. The disclosure arrived on September 28 as the minority staff of the Senate Permanent Subcommittee on Investigations released a report and asked the Treasury Department to examine Tether's compliance practices. Tether's statement.

The issuer identified two major parts of the total. In April, it says it supported the freezing of more than $344 million across two addresses after receiving information from the Office of Foreign Assets Control and U.S. law enforcement. In July, more than $130 million across four TRON wallets was frozen as Treasury expanded its Central Bank of Iran designation. Tether describes the roughly $550 million figure as the total across Iran-linked actions in 2026, so the two examples are components rather than a complete itemized accounting.

The Senate minority letter presents a different assessment of the control record. It says investigators examined wallets sanctioned, targeted for seizure or otherwise identified for links to Iran and aligned groups, and found that 84% transacted exclusively or nearly exclusively in USDT. The letter also alleges that some publicly identified wallets remained active without being blacklisted. It asks Treasury to investigate possible compliance failures and provide records by October 9. Those are allegations and a request for review, not a finding that Tether violated the law. Senate letter.

Reuters reported that the investigation covered 846 wallets sanctioned by Israel or the United States in connection with Iran. The company and Senate figures measure different things: Tether's figure is the value frozen during issuer-supported actions, while the Senate percentage describes token usage across the wallet set it reviewed.

For stablecoin users, the episode shows both sides of issuer-controlled sanctions tooling. An issuer can prevent listed balances from moving after authorities identify an address, but the effectiveness of that control depends on when addresses are identified, what evidence is shared and how quickly a freeze is applied. The next concrete evidence will be any Treasury response, additional address-level disclosure or enforcement action resulting from the Senate request.