The Tether Iran report: a Senate probe finds USDT behind Iran's shadow banking

The Tether Iran report, released on 28 September 2026 by minority staff of the Senate Permanent Subcommittee on Investigations, found 84% of 846 Iran-linked sanctioned wallets transacted almost entirely in USDT. It also documents one freeze about nine months late. The findings are preliminary with no legal effect, but the screening lessons apply now.

• Minority staff of the Senate Permanent Subcommittee on Investigations, under Ranking Member Richard Blumenthal, published a 28-page report on 28 September 2026.
• It analysed 846 wallets designated by OFAC and Israel's National Bureau for Counter Terror Financing between June 2021 and August 2026.
• In one Hizballah-linked case, more than 34.6 million dollars left Israeli-designated wallets before Tether froze them.
• Tether's same-day statement says actions involving USDT froze about 550 million dollars of Iran-linked assets in 2026.
• Nothing in the report creates a new obligation, but existing blocking and SAR duties already cover the exposure it describes.

What did the Senate report find?

The Tether Iran report concludes that USDT became the dominant token in Iran's crypto sanctions evasion network from 2023. Of 846 wallets designated for links to Iran and its proxies, 84% transacted exclusively or nearly exclusively in USDT. The authors call the token "a significant financial lifeline within Iran's shadow banking network."

The report, titled "Tethered to Terrorism: Crypto and Iran's Shadow Banking Network", sets out three findings. Tether had become a primary illicit payment system for Iran. It served as a payment mechanism linking Iran to Hamas, Hizballah and the Houthis. And its repeated failure to freeze illicit wallets created a permissive environment. The subcommittee wrote to Tether on 4 June 2026 and says the company had not responded by publication.

Two networks carry the largest figures. Alireza Derakhshan and Arash Estaki Alivand are Iranian nationals OFAC designated in September 2025 for running front companies behind Iranian oil sales and military procurement. The Modex Exchange Company is a brokerage, reportedly run by Iranians, that leaked Central Bank of Iran letters describe buying USDT for the central bank.

The report defines "predominantly" as more than 80% of a wallet's dollar volume. USDC, the second largest stablecoin, appeared only in a few transactions by one sanctioned Iranian exchange.

How did the freezes lag the designations?

In the Tether Iran report, freezes trailed designations by about nine months in the clearest case, and some never came. Israel designated 39 wallets of a Hizballah-linked launderer in June 2023, and Tether froze 34 of them only in March 2024. More than 34.6 million dollars left in between.

That launderer is Tawfiq Muhammad Sa'id Al-Law. Tether froze five of his 39 wallets but left the other 34 until shortly before OFAC sanctioned Al-Law himself. The outflows during that gap ran through large exchanges. From 2021 to May 2023, the report found no Tether freezes of wallets designated by Israel's counter terror financing bureau. The report also found wallets posted publicly in December 2025 by Babak Zanjani, a sanctioned Iranian financier, still not blacklisted in September 2026. Its verdict on the model is blunt: "Solely relying on the reactive freezing of wallets after designations will not work."

Tether's statement, published the same day, does not mention the report. It says Tether froze more than 344 million dollars across two addresses in April 2026 on information from OFAC and US law enforcement, and that OFAC listed those addresses for the Central Bank of Iran the following day. It reports more than 130 million dollars frozen across four wallets in July, and more than 22 million USDT frozen in over 40 cases referred by Israel's bureau. Chief executive Paolo Ardoino said "Tether can act when credible information is provided by law enforcement."

What does the Tether Iran report change for your obligations?

The report changes no rule, but it shows where existing duties fail when a firm leans on the issuer. For a US exchange, bank or payment firm touching USDT, obligations run through OFAC blocking, SAR filing and counterparty due diligence. From the GENIUS Act's expected effective date of 18 January 2027, issuer diligence follows.

Sanctions comes first. OFAC lists digital currency addresses as identifiers on the Specially Designated Nationals list, and once an address is listed, US persons must block it themselves whether or not the issuer has frozen it. Civil liability is strict, so an issuer's delay is no defence. Israeli NBCTF designations do not create a US blocking duty, but they are strong risk signals worth screening. Screen deposit and withdrawal addresses at the transaction, not in a nightly batch, and add exposure rules for wallets one or two hops from a listed address. The report shows designated actors rotating addresses within months, which is why an OFAC check on exact matches alone falls short.

Suspicious activity reporting has a specific hook. FinCEN's alert FIN-2026-Alert002 of 11 May 2026 describes digital assets as "one leg of Iran's shadow banking network." It names movement between large volume stablecoin issuers as a typology. It asks filers to enter the key term FIN-2026-Alert002 in SAR field 2 and the narrative, and to select field 33(a) for terrorist financing. A Suspicious Activity Report on flows matching the report's patterns should cite the alert.

Customer due diligence on counterparties is the third duty. The report traces Iranian funds entering through offshore exchanges, over-the-counter desks and "cashdesks" of the kind it calls no-KYC venues. Nested exchange accounts and OTC counterparties need enhanced due diligence, including their own screening controls and freeze history.

Issuer diligence is the fourth. Treasury's August 2026 proposal, still pending, would let a service provider rely on a foreign issuer's representation that it can obey a lawful order only after reasonable due diligence. We covered how that proposal works. A published congressional record of missed freezes is information a diligence file should address.

European firms reach the same conclusion by other routes. Council Regulation (EU) No 267/2012 freezes funds of listed Iranian persons, and Regulation (EU) 2023/1113 requires originator and beneficiary information on crypto-asset transfers. The first puts the freeze duty on the firm holding the funds; the second gives it that data to screen each transfer before an issuer acts.

What is still uncertain about the report and its impact?

The main uncertainty about the Tether Iran report is legal status. This is a minority staff report of one Senate subcommittee, labelled preliminary findings. It carries no enforcement weight, no agency has charged Tether, and Tether's same-day statement stresses its cooperation with authorities. Firms should treat the findings as risk information, not as a finding of law.

The methodology leaves questions. The headline counts wallets, not dollars, and the two component sets, 757 Israeli and 101 OFAC wallets, sum to more than 846 without an explanation of overlap. Attribution relies on Israeli seizure orders, which the report concedes were sometimes published weeks or months after signature. Some freeze delays may reflect when an order became public rather than when Tether could have acted. Tether's statement also cites Elliptic research that it blacklisted 39 of the 187 IRGC-linked addresses Israel's bureau listed in September 2025, freezing about 1.5 million dollars. That shows action, though the statement does not say how many of the other 148 addresses held USDT at all.

The liability split is unresolved. The GENIUS Act licensing regime is not yet in force, USDT is issued offshore, and the report says Tether has described its OFAC compliance as voluntary. The June 2026 FinCEN and OFAC proposal would require licensed issuers to block, freeze and reject impermissible transactions and run an effective sanctions programme. How far that reaches a foreign issuer depends on the section 18(a) comparable regime route, and Treasury has not yet found any foreign regime comparable.

Displacement is a further risk. The report notes that Bitcoin and Ethereum lack a central freeze function. Faster stablecoin freezes could push flows toward assets no issuer can stop, moving the detection burden onto exchanges and their transaction monitoring.

How does this compare with earlier crypto sanctions cases?

The closest precedent is Binance, and the contrast is in consequence. Treasury said in 2023 that Binance had matched trades between US users and users in sanctioned jurisdictions including Iran, and Binance paid record penalties. This report produces allegations and a request for scrutiny, not a penalty.

The Treasury announcement of 21 November 2023 described the FinCEN and OFAC amounts as the largest in each agency's history. FinCEN's alert names Zedxion as an OFAC-designated stablecoin issuer tied to Iran, so sanctioning an issuer directly already has precedent. The Tether Iran report asks the Department of Justice, the SEC and OFAC to hold stablecoin issuers accountable for repeated failures. Our coverage of the Xinbi Guarantee sanctions shows OFAC also targeting stablecoin-heavy marketplaces.

How should compliance teams respond?

Start with exposure to the flows the Tether Iran report describes. Pull 2026 USDT flows touching the address clusters in the report's attachment and in OFAC's Iran-related designations, and check whether any cleared your platform after designation. Where they did, assess the blocking and reporting position with counsel, and file SARs citing FIN-2026-Alert002 where the facts support it.

Then close the timing gap. Move address screening to the transaction, add hop-based exposure rules, and document every list update with a timestamp. Review nested exchange and OTC counterparties for their own freeze record. For issuer diligence ahead of the Act's expected effective date, record what your firm knew about each issuer and when.

Zyphe helps with the counterparty and list side of this. Our sanctions screening checks names against current lists, KYB verification resolves who owns and controls an exchange or OTC counterparty, and every check leaves an exportable audit trail with no central store of identity records to breach. To see how it fits your programme, book a demo.

The bottom line

The Tether Iran report is not law, and its numbers deserve scrutiny, but its core lesson is sound. Issuer freezes can trail designation by months, and sometimes never come, and in one case more than 34.6 million dollars left during that gap. Teams running KYC and AML on stablecoin flows should own the timing themselves: screen at the transaction, document diligence on issuers and counterparties, and file with the alert's key term.

Cited sources

• Senate PSI minority staff report, Tethered to Terrorism: Crypto and Iran's Shadow Banking Network, 28 September 2026 (PDF)
• Tether statement: Tether Has Supported Nearly $550 Million in Iran-Linked USDT Freezes, 28 September 2026
• FinCEN Alert FIN-2026-Alert002 on IRGC sanctions evasion, 11 May 2026 (PDF)
• FinCEN and OFAC proposed rule: Permitted Payment Stablecoin Issuer AML/CFT and Sanctions Compliance Program Requirements, 91 FR 37840
• Treasury NPRM: GENIUS Act Regulations on Payment Stablecoin Issuance, Offer, and Sale, 18 August 2026
• Treasury press release on the Binance settlements, 21 November 2023
• Council Regulation (EU) No 267/2012, restrictive measures against Iran
• Regulation (EU) 2023/1113 on information accompanying transfers of funds and crypto-assets