Network facts
What is a transaction ID in crypto?
Every transaction on a blockchain has an identifier — a txid or transaction hash — that names it uniquely on that network. It is how a payer proves a payment was sent, how a merchant matches it to an invoice, and what a block explorer takes to show its status.
What it is
A transaction id is a hash of the transaction’s contents, computed when it is created. It does not change once the transaction is broadcast, so anyone holding it can look the transaction up on that network: its sender, recipient, amount, the block that included it and how many blocks have followed.
It names a transaction on one network only. A hash from Ethereum means nothing on Bitcoin, and the same payment sent on two networks would have two unrelated ids.
Where a payer finds it
In the wallet that sent the payment, on the transaction’s detail screen, usually with a link to a block explorer. Copying it from there is the fastest way to show a merchant that a payment went out.
Where a merchant sees it in Unheld
On the invoice: each payment detected on an invoice is listed with its transaction hash, and the same hash is in the webhook Unheld sends when the invoice changes state, as the payment’s txHash field. A merchant reconciling by hand matches that hash to the payer’s; a merchant reconciling by code reads it from the webhook.
How to check a transaction’s status
Paste the id into the network’s block explorer. It shows whether the transaction is in a block, how many confirmations it has, and whether it succeeded — on Tron and the EVM networks a transaction can be included and still fail, and the explorer says so. The confirmations pages on this site say how many confirmations each network needs before Unheld credits a payment.
What it looks like on each network
| Network | Called | Shape |
|---|---|---|
| Bitcoin | Transaction ID (txid) | 64 hexadecimal characters, no prefix |
| Ethereum | Transaction hash | “0x” followed by 64 hexadecimal characters |
| Base | Transaction hash | “0x” followed by 64 hexadecimal characters |
| Polygon PoS | Transaction hash | “0x” followed by 64 hexadecimal characters |
| BNB Chain | Transaction hash | “0x” followed by 64 hexadecimal characters |
| Lisk | Transaction hash | “0x” followed by 64 hexadecimal characters |
| Tron | Transaction ID | 64 hexadecimal characters, no prefix |
| XRP Ledger | Transaction hash | 64 hexadecimal characters, usually written in capitals |
Questions about transaction ids
What is a txid?
Bitcoin’s name for the transaction id: a hash of the transaction, 64 hexadecimal characters, unique on the Bitcoin network. Other networks call the same thing a transaction hash.
How do I check a TRC20 transaction?
With its transaction id on a Tron block explorer, which shows the transfer, the contract it called, whether it succeeded and how many blocks have confirmed it.
Can two transactions have the same id?
Not on one network: the id is a hash of the transaction’s contents. Two different networks can in principle produce the same hash for unrelated transactions, which is one more reason the network always has to be named with the id.