Direct answer: OFAC (the US Treasury's asset-control office) publishes a list of sanctioned people and entities — the SDN list — which since 2018 includes specific cryptocurrency addresses. Sending funds to or receiving funds from those addresses can trigger an immediate freeze by Tether and by exchanges, plus legal consequences for whoever transacts with them. Our checker cross-references the updated OFAC list on every lookup.
Why it matters even if you're not in the US
OFAC is a US agency, but its list is the standard applied by Tether, Circle and virtually every global exchange — including the ones you use for P2P, wherever you live. If you receive USDT that passed through a sanctioned address (a flagged mixer, an entity from a sanctioned country, a ransomware group), the exchange's compliance system detects it and your account can be suspended while you explain the origin. Intent isn't required: contact is enough.
Typical cases that trip the alarm
- Funds that passed through sanctioned mixers (Tornado Cash is the best-known case).
- Addresses linked to ransomware groups or darknet markets.
- Wallets of entities from comprehensively sanctioned countries.
Related: OFAC is one of the lists feeding the Tether blacklist — understanding both gives you the full risk map.
Frequently asked questions
Where is the official list?On OFAC's site (sanctionslist.ofac.treas.gov). Our checker already cross-references it with the address you look up, along with the other lists.
How often is it updated?OFAC adds addresses on no fixed schedule; our local base updates daily.
More checker guides
GuideUSDT wallet frozen: what it means and what you can doGuideChecking a wallet before a P2P trade: the habit that saves your accountGuideThe Tether blacklist: how the USDT freeze button worksGuideThe 6 USDT scams that repeat the most (and the habit that disarms them)GuideChecking USDT on Ethereum (ERC20): what changes versus TRON