What is a Satoshi Test?

Many exchanges or brokers require a "Satoshi Test" to confirm you own the Bitcoin withdrawal address you provide. This test involves sending a very small amount of bitcoin (called satoshis) from that specific address, proving you control it. While these tests aim to improve security, they can sometimes be an extra step for managing your crypto yourself. You can explore more about Satoshi Tests and potential alternatives like AOPP in our blog post: Satoshi Tests Hinder Self-Custody, but AOPP Can Fix It 

This guide will walk you through performing a Satoshi Test using your BitBox and the BitBoxApp.

Step 1: Enable Coin control in the BitBoxApp

Coin control is an advanced BitBoxApp feature. It lets you choose specific inputs (UTXOs or Unspent Transaction Outputs) for your transactions. Think of UTXOs as individual 'coins' or distinct parts of your bitcoin balance, each associated with a specific address. You'll need to enable Coin control to select the precise address your exchange wants you to verify.

1. Open the BitBoxApp and navigate to Settings.
2. Select the Advanced settings tab.
3. Toggle the switch to Enable coin control.

Step 2: Perform the Satoshi Test transaction

With Coin control enabled, you're ready to create the verification transaction.

1. In the BitBoxApp's left sidebar, select the Bitcoin account you want to use for the Satoshi Test.
2. Click Send in the main window. (Remember, this is only active if you have bitcoin in the account.)
3. A Coin control button will now be visible. Click it to open the Coin control panel, which lists your available UTXOs.
4. Select the correct UTXO: From the Coin control panel, carefully choose a UTXO that belongs to the exact Bitcoin address your exchange or broker has asked you to verify.

Crucial: Do not select any UTXO labeled as a "Change address." Change addresses are internal addresses created by the BitBoxApp to manage transaction leftovers. They don't appear in your regular transaction history (they are only visible in Coin control) and are unsuitable for a Satoshi Test.

 

4. Once you've identified and selected an appropriate UTXO (from the address your broker wants to verify and not a change address), click OK. The inputs you selected will now be used for your transaction.
5. Now, carefully follow the instructions provided by your exchange or broker:
   • Enter the Bitcoin address they specified as the recipient.
   • Enter the exact small amount of bitcoin they require for the test.
6. Review all transaction details on the BitBoxApp screen (recipient address, amount, transaction fee).
7. Verify on your BitBox device: Your BitBox hardware wallet will display the transaction details for final confirmation. Meticulously review the recipient address and amount on the device's screen. This is your most important security check.
8. If all information is correct, confirm the transaction on your BitBox device to send it.

You've now successfully performed a Satoshi Test for your withdrawal address! Your exchange or broker should soon recognize this transaction and confirm your address ownership, allowing you to proceed with your withdrawals.