U.S. Uses Tether to Freeze Nearly $475M Linked to Iran

U.S. authorities used the issuer Tether to freeze roughly $475 million in USDT held on the Tron blockchain, blocking addresses that U.S. officials link to Iran.

The action combines a July 14 designation of four Tron wallets holding about $131 million and an earlier April freeze of more than $344 million across two other Tron addresses. The Office of Foreign Assets Control identified the July addresses as connected to the Central Bank of Iran, also known as Bank Markazi.

Treasury Secretary Scott Bessent described the designations as part of a broader effort to disrupt networks the U.S. says Iran uses to evade sanctions and added, “we would continue to trace and restrict the movement of those funds.”

Tether controls the USDT token contracts on several blockchains and can add wallet addresses to a blocklist so tokens at those addresses cannot be moved or redeemed. Blocked balances remain visible on the public Tron ledger but are restricted at the protocol level. In cases where legal authority permits, Tether can cancel tokens at one address and reissue an equivalent amount elsewhere.

The freezes form part of a Treasury initiative called Operation Economic Fury, which targets cryptocurrency exchanges, intermediaries and blockchain addresses that U.S. officials say have helped Iran obtain and move dollar-denominated assets outside the banking system. In June, OFAC sanctioned four exchanges-Nobitex, Bitpin, Ramzinex and Wallex-identifying them as major conduits for Iran’s digital-asset activity.

Blockchain analysis firms report substantial crypto inflows into Iranian addresses. One estimate put inflows at more than $7.78 billion in 2025, with addresses linked to the Islamic Revolutionary Guard Corps accounting for about half of that activity and receiving over $3 billion. U.S. officials said that by late May they had seized or frozen nearly $1 billion in cryptocurrency connected to Iran under the wider campaign.

Tether has set compliance measures for sanctions enforcement. In December 2023 the company adopted a policy to disable tokens held in wallets on OFAC’s sanctions list. Tether also reports cooperation with hundreds of law-enforcement agencies, contributing to thousands of cases and to the freezing of more than $4.4 billion in digital assets, including amounts tied to U.S. authorities.

The asset freezes draw a distinction between issuer-controlled stablecoins and decentralized cryptocurrencies. Bitcoin and other decentralized coins cannot be stopped from moving by a single company if the holder controls the private keys. USDT transfers can be blocked or rendered unusable because the issuer controls the token contract.

About $184 billion of USDT is in circulation, and the token is widely used on exchanges, in payment services and in informal financial networks. Tether’s controls therefore affect how dollar-linked value moves on public blockchains.