# Methodology: how TRCBeacon checks USDT TRC20 addresses

**Short answer.** TRCBeacon reports whether a TRON address is on the Tether blacklist and whether it matches the OFAC sanctions lists, at the time shown. It does not score risk and does not give a legal opinion. The address you check is not stored.

## Where does the Tether data come from?

The blacklist is a part of the USDT contract on TRON, `TR7NHqjeKQxGTCi8q8ZY4pL8otSzgjLj6t` ([Tether](https://tether.to/en/supported-protocols/)). We build our copy from the contract's `AddedBlackList` and `RemovedBlackList` events, and spot-checks read the status directly through our own TRON node, not a third-party API.

## Where does the OFAC data come from?

From the official files on treasury.gov: the SDN Advanced XML and the Consolidated list ([OFAC SDN lists](https://ofac.treasury.gov/specially-designated-nationals-and-blocked-persons-list-sdn-human-readable-lists)). The job wakes up every hour, downloads the files every 24 hours, retries after 6 hours on failure and raises an alert if the data is older than 48 hours.

## What does "clean" mean?

"Clean" means only that the address was not found on these two lists at the time shown. OFAC itself says its digital currency address listings are not likely to be exhaustive ([OFAC FAQ 562](https://ofac.treasury.gov/faqs/562)).

## What does the check not do?

- It does not score risk or trace fund flows.
- It does not label funds as "dirty" or "clean".
- It does not cover other sanctions regimes or national lists.
- It is not legal advice and not a compliance conclusion.

## How is the privacy of a check handled?

The checked address is not stored or logged, and it is not kept together with your IP address. The rate limiter uses an HMAC of the IP with a salt that changes every 24 hours, so it cannot be reversed to an IP. Limits are 20 checks per minute and 500 per day per hash. Server logs are kept for 90 days.

## Facts at a glance

| Fact | Value | Source |
| --- | --- | --- |
| USDT contract on TRON | `TR7NHqjeKQxGTCi8q8ZY4pL8otSzgjLj6t` | [Tether](https://tether.to/en/supported-protocols/) |
| Tether data | Contract events and own TRON node | This page |
| OFAC data | SDN Advanced XML and Consolidated list | [treasury.gov](https://ofac.treasury.gov/specially-designated-nationals-and-blocked-persons-list-sdn-human-readable-lists) |
| OFAC download | Every 24 hours, alert at 48 hours | This page |
| Check limits | 20 per minute, 500 per day | This page |

Try the [checker](/tools/usdt-trc20-checker/) or read the guide [How to check if a USDT address is frozen](/guides/how-to-check-if-usdt-address-is-frozen/).


## Frequently asked questions

### Do you store the address I check?

No. It is not stored or logged and is not kept together with the IP.

### Is the result AML scoring?

No. It reports Tether blacklist and OFAC list matches only.

### How fresh is the OFAC data?

Downloaded every 24 hours; an alert is raised after 48 hours.

### Does a clean result guarantee safety?

No. It means no match on these lists at the time shown.