Satoshi test

The platform asks the customer to send an exact small amount, such as 0.00001234 BTC, from the external address they want to register to a deposit address controlled by the platform. Because only the owner of the private key can sign such a transaction, receiving that precise amount proves control of the address. Exchanges often refund or credit the test amount.

The check became common in Europe and Switzerland with the travel rule. Under the EU's Transfer of Funds Regulation, applied from December 2024, crypto-asset service providers must verify that customers own self-hosted wallets for transfers above €1,000. Alternatives include signing a message with the wallet's private key or uploading a screenshot, but the satoshi test works with almost any wallet.

The method costs a network fee and some delay, and it proves only that the person controls the address at that moment, not who they are. Scammers have also abused the idea, asking victims to send a small test payment to start a fake verification. Legitimate platforms show the request inside their own app or website, not via messages or calls.