A Satoshi test is an on-chain Bitcoin transaction that a service requests to check whether you can spend from a specific Bitcoin address. Use this guide only when the service explicitly asks for a Satoshi test and has given you the exact source address, destination address, amount, unit, and confirmation requirement. If the request is unclear, ask the service which verification method and exact transaction details it accepts before continuing.

The BitBoxApp’s Coin Control feature lets you select a spendable output tied to the required source address. The transaction moves bitcoin, incurs a network fee, and creates a public record. It cannot be reversed after confirmation. A Satoshi test shows that you could authorize this particular spend; it does not prove your identity, legal ownership, or control of every address in your wallet.

Check the requested address

First confirm that the exact source address belongs to the Bitcoin account you intend to use. The BitBoxApp keeps Bitcoin accounts separate, so check the account named or implied by the service’s request.

1. In the BitBoxApp’s left sidebar, select the relevant Bitcoin account.
2. At the top of the account overview, select Account info, then View used addresses.
3. Search the complete address under both Receive addresses and Change addresses. Select the matching result to expand its details.

If the exact address appears, the selected account generated it. Continue to check its confirmed output. If it does not appear in either tab, check any other relevant Bitcoin account. If you still cannot find it, stop and confirm the source address with the service; do not substitute another address.

For more detail about opening this view, searching addresses, and the difference between receive and change addresses, see How to view used addresses in the BitBoxApp.

Check for a confirmed spendable output

From the expanded address details, select Open in external block explorer. The BitBoxApp opens the address in the mempool blockchain explorer. The explorer shows public blockchain data, not wallet ownership; opening it also sends the public address query to an external website.

Check whether the address has a confirmed balance and at least one confirmed unspent transaction output (UTXO). A UTXO is a portion of bitcoin received by an address that has not yet been spent. The result determines your next step:

The screenshot below shows an example of an empty address. Past activity or a total received amount does not mean the address currently has a spendable UTXO.

Fund the confirmed source address if it is empty

Use this section when the exact address appears in Used addresses, has no confirmed UTXO, and the service has confirmed that the Satoshi test must come from that address. Funding creates the output you will later select for the test. It is a separate on-chain transaction: it incurs another fee, reuses the address, and cannot be reversed after confirmation.

Before sending, make sure you have enough bitcoin to cover the required test amount and the later test transaction’s network fee. The funding transaction has its own fee as well.

1. In Used addresses, expand the required address and select Copy address to copy it in full.
2. In the BitBoxApp, open the Bitcoin account you will fund it from and select Send.
3. Paste the copied address into Receiver address. Compare it character by character with the address supplied by the service.
4. Enter enough bitcoin to cover the Satoshi-test amount and its expected fee. Do not send only the test amount.
5. Select Review and check the recipient, amount, and network fee in the BitBoxApp. Verify the recipient address, amount, and fee on the BitBox hardware-wallet display. Confirm on the device only if they match your intended funding transaction.
6. Wait for the funding transaction to confirm. Then check the address again in the external explorer and confirm it has a sufficient confirmed UTXO.

If you cannot fund the address and cover both transaction fees, ask the service for another accepted verification method. Use only the exact source address confirmed by the service.

Enable coin control

If Coin Control is already enabled, continue to the test. Otherwise, in the BitBoxApp open Settings, select Advanced settings, and turn on Enable coin control. The setting makes Coin Control available while you prepare a Bitcoin transaction. For a general walkthrough of the feature, see how to use Coin Control in the BitBoxApp.

Perform the Satoshi test

Before you begin, make sure the requested address has a confirmed UTXO and that you have the service’s exact source address, destination address, amount and unit, confirmation requirement, and any restriction on which output or inputs to use. If the service supplied an outpoint, keep it available. An outpoint identifies one specific transaction output.

The steps below select a matching output in Coin Control, prepare the requested transaction, and verify its details on your BitBox before you authorize it. The screenshots are optional visual references; follow the written directions even if you cannot view them.

Step 1: Open the correct account and select Send

In the BitBoxApp, select the Bitcoin account where you found the required address. Select Send to open that account’s Bitcoin send form. Check the account name again before continuing; Coin Control will list outputs from the selected account.

Step 2: Open Coin Control

On the right side of the send window, select Coin control. The Send from output panel opens and lists spendable UTXOs for the account you selected. If Coin Control is not available, enable it under Settings → Advanced settings → Enable coin control, then return to the send window.

Step 3: Find and select the matching output

In the Send from output panel, find a row whose full address matches the source address required by the service. Each row shows an amount, Date, Address, and Outpoint. If the service specified an outpoint, compare it as well; do not select an output just because its amount looks right.

Select the checkbox at the left of one matching row. Its value must cover the requested test amount and the network fee. Confirm that the selected row is the only one selected unless the service has confirmed that it accepts a transaction with multiple inputs and specified which inputs are acceptable.

The blue Change label marks an output created as change. The red Address re-used label warns that the address has been used more than once. Neither label confirms that the output matches the service’s required source; check the complete address and any specified outpoint.

Select Continue to return to the send form with your output selection.

Step 4: Enter the exact destination and amount

Enter the destination address supplied by the service in Receiver address and enter the exact requested amount in the cryptocurrency amount field. Match the amount’s unit exactly: an amount written in satoshis is not the same as the same digits entered as BTC. Recheck the full destination address and amount against the original request before continuing. The Note field is optional; its contents stay in the BitBoxApp and are not included in the Bitcoin transaction.

Step 5: Check what happens to the selected UTXO

A Bitcoin transaction spends each selected UTXO in full. If the selected output is worth more than the test amount and fee, the remainder returns to your wallet as a new change output. The original source address may then have no spendable output. If the service expects a later transaction from that same address, stop and ask it how this change affects its requirement before sending.

If one matching output is insufficient, do not select unrelated outputs or add inputs automatically. Ask the service whether it accepts multiple inputs and, if so, which exact inputs or source-address conditions it requires.

Step 6: Verify the transaction on your BitBox

Select Review in the send form and check the prepared transaction in the BitBoxApp. Then check the recipient address, amount, and network fee on your BitBox hardware-wallet display. Confirm on the device only when those details match the service’s request and your intended transaction. If anything differs or is unclear, reject the transaction and compare the details again.

Step 7: Wait for the service to accept the test

After authorizing the transaction, wait for it to be broadcast and reach the confirmation state the service requires. Share the transaction ID only if the service asks for it. The test is complete when the service confirms that it accepted the transaction; a blockchain confirmation alone does not establish acceptance.

If the test does not work

The address is not listed in Used addresses

Check the intended Bitcoin account and search both Receive addresses and Change addresses. If the exact address is still missing, ask the service to confirm it. Do not substitute another address.

The address has no confirmed UTXO

Wait if an incoming transaction is still unconfirmed. If the address is empty, confirm with the service that it still requires the Satoshi test from that exact address. Once confirmed, and after finding the address in your account, follow the funding steps.

The address or UTXO is not in Coin Control

If you funded the address, confirm that the funding transaction has confirmed. Also check that you opened the same Bitcoin account where you found the address. Coin Control lists spendable UTXOs, not every address the account has used. If the address has a confirmed UTXO but it still does not appear, contact BitBox Support with the BitBoxApp version, hardware model, and public address.

The UTXO does not cover the amount and fee

The BitBoxApp will not let you continue when the selected output is insufficient. Ask the service whether it accepts multiple inputs or another verification method before adding inputs. A transaction built from other inputs may not meet its exact source-address requirement.

The transaction is unconfirmed

Wait for the service’s required confirmation state. Do not create another funding or Satoshi-test transaction just because the first one is still unconfirmed.

Incorrect details were broadcast

A broadcast transaction cannot be edited, and it cannot be reversed after confirmation. Contact the service and ask what it requires next. Do not send another transaction unless the service confirms that a repeat is necessary.

The service rejects a confirmed transaction

Ask the service to reconfirm the required source address, destination address, amount and unit, confirmation threshold, and whether it accepts the transaction’s inputs. Acceptance rules are set by the service.

Contact BitBox Support if the BitBoxApp, Coin Control, or hardware-wallet steps do not behave as described. Share only the non-secret details needed to investigate, such as the app version, hardware model, public address, or transaction ID. Never share wallet secrets or a wallet backup.