The money has landed, but you don’t really know who sent it. Maybe a P2P buyer, maybe a new client, maybe your exchange just emailed asking about the source of a deposit. This is where you check the transaction by hash: take the ID of that one transfer and find out what kind of funds actually arrived. This guide covers what a hash is, how it looks on different chains, where to find it, and what to do with the result.
What is a TXID?
A TXID (transaction ID, also called a transaction hash or TxHash) is a unique string that points to exactly one transfer on a blockchain.
It is produced by running the transaction data through a cryptographic hash function. Two different transfers never share a hash, and nobody can edit one after the fact. Think of it as a public receipt number. Anyone can paste it into a block explorer and see who sent what to whom, and when.
The explorer will also show the status (confirmed, pending or failed), the block number, confirmations and the network fee. What it won’t show is risk. A transaction hash lookup tells you which address the coins came from one step back, but not whether that address is tied to a mixer or a scam. That part needs an AML check.
What a transaction hash looks like on Bitcoin, Ethereum and Tron
Hashes are easy to tell apart from addresses. Addresses have familiar prefixes (bc1, 1 or 3 on Bitcoin, 0x plus 40 characters on Ethereum, T on Tron). A hash is longer and uses only hexadecimal characters: digits 0 to 9 and letters a to f.
| Network | Hash format | Shape (shortened, made up) | Explorer |
|---|---|---|---|
| Bitcoin | 64 hex characters, no prefix | 9f2c7a10…4be81c | mempool.space, Blockchair and other Bitcoin explorers |
| Ethereum (ERC-20) | 0x followed by 64 hex characters | 0x7d41e0b3…a92f | Etherscan |
| Tron (TRC-20) | 64 hex characters, no prefix | b3f1c2a9…d0e7 | Tronscan |
Bitcoin and Tron hashes look the same at a glance. If you’re not sure which chain a hash belongs to, try Tronscan first. If nothing comes up, it’s probably Bitcoin.
A USDT transfer on Tron or Ethereum is technically a smart contract call. Its hash looks just like any other, and the explorer shows both the contract call and the token movement inside it.
Where to find the transaction hash
Short answer: in your transaction history, inside the details of the transfer.
In a self-custody wallet
- Open the asset (say, USDT TRC-20) and go to its history.
- Tap the transaction.
- Look for Hash, TxHash or Transaction ID and copy it.
- No such field? Tap “View on explorer”. The hash will be in the URL and at the top of the page.
This works roughly the same in TronLink, Trust Wallet, Exodus and MetaMask.
On an exchange
Check the deposit or withdrawal history. The column is usually labeled TXID or Hash, sometimes hidden behind a link icon. One catch: transfers between two users of the same exchange often never touch the blockchain. They show up as “Internal transfer” and have no hash to check.
Common mistakes
- Copying the sender’s address instead of the hash.
- Picking the wrong network. USDT lives on both Tron and Ethereum, and a hash only exists on its own chain.
- Losing a character when copying on a phone. Count them: 64, plus
0xon Ethereum. - Using the exchange’s internal withdrawal ID, which is a different thing from the on-chain TXID.
Also wait for the transfer to confirm. A pending transaction may not show up in the explorer yet.
Hash check vs address check
They answer different questions. An address check looks at the whole wallet: every transfer that has passed through it and its connections. A hash check looks at one transaction and calculates risk for a specific side, the recipient if you are receiving, the sender if you are sending.
| Address check | Hash (TXID) check | |
|---|---|---|
| What gets analyzed | All funds that moved through the wallet, plus its connections | One specific transaction |
| Whose risk | The address itself | The recipient (if you’re receiving) or the sender (if you’re sending) |
| When to use it | Before a deal: new counterparty, P2P purchase, checking your own wallet | After a transfer has arrived |
| Typical question | “Should I deal with this person at all?” | “What did I just receive, and how do I explain it to my exchange?” |
| What you need | A wallet address | A transaction hash |
Most people end up using both: check the counterparty’s address before the deal, then the incoming transaction after it. Our guide to checking a crypto wallet address covers the first part.
How to check a transaction by hash in @AMLmexmBot
mexm AML is a Telegram bot, @AMLmexmBot, that checks wallet addresses and transaction hashes on Bitcoin, Ethereum and Tron; the first check is free. No sign-up on a website, and the report arrives in the chat.
- Copy the hash from your wallet, exchange or explorer.
- Open the AML bot in Telegram and press Start.
- Choose the network: Bitcoin, Ethereum (ERC-20) or Tron (TRC-20).
- Send the hash as a message.
- Read the report and save it.
After the free check, you buy packages inside the bot. As of November 2026, prices start at $0.30 per check in a package. Plans and details are on the mexm AML page.
Reading the report
The report gives you an overall risk score in percent, the categories of fund sources, and the share of money from each one. The score reflects the combined weight of “clean” and “dirty” funds behind the transfer.
- Below 40%: low risk, generally fine to work with.
- 40% to 50%: medium risk, look closer at the sources.
- 50% and above: high risk. Better to walk away from the deal.
Sources fall into more than 20 categories across three groups. Dangerous ones include darknet markets, scams, mixers, stolen funds, sanctions and ransomware. Suspicious ones include unlicensed exchanges and P2P, low-KYC crypto ATMs and DEXs. Trusted ones include licensed exchanges and P2P, custodial online wallets, payment processors and miners.
Don’t stop at the headline number. Six percent from a mixer with the rest from a licensed exchange is one story. Thirty percent from a scam address is a very different one.
An incoming transfer shows high risk. Now what?
Leave the coins alone. Then work through this:
- Don’t move the funds around. No forwarding to your other wallets, no splitting, no swapping. Extra hops muddy the trail and can look like an attempt to hide it.
- Save the report and the hash, along with screenshots of your chat with the sender and proof of what the payment was for.
- If the coins went to an exchange and it asked questions or limited withdrawals, contact support. Attach the hash, the report and a short note on who sent the money and why.
- If the deal is still open (a P2P trade in progress, for example), don’t confirm it until you’ve sorted things out.
The exchange makes its own decision, and nobody can promise the outcome. The report shows you checked the deposit and are acting in the open. It is not a legal opinion, and for large sums talking to a lawyer makes sense.
One more thing about USDT. Tether can freeze tokens on blacklisted addresses at the smart contract level, with no exchange involved. So funds linked to scams or sanctioned addresses carry risk even in your own wallet.
The short version
A transaction hash is the ID of one specific transfer: 64 hex characters on Bitcoin and Tron, the same with 0x in front on Ethereum. Find it in your wallet or exchange history, run it through @AMLmexmBot, and keep the report. If the score comes back high, leave the funds where they are and take the report to the platform’s support team.