Bull Bitcoin became the first exchange to support Payjoin privacy deposits and withdrawals as well as default transactions

Bull Bitcoin, a Bitcoin-exclusive exchange, announced a deep integration with Payjoin, claiming to be the world's first Bitcoin exchange to offer Payjoin as a deposit and withdrawal option, introducing two new concepts: "default Payjoin" and "Payjoin transaction." Founded in 2013 by Francis Pouliot in Canada, Bull Bitcoin is the longest-operating Bitcoin-exclusive exchange globally, with its non-custodial platform allowing users in Canada, Europe, and Latin America to buy Bitcoin directly into their wallets or sell Bitcoin to bank accounts. The company also developed the free and open-source Bitcoin self-custody wallet BULL Wallet, which has been self-funded since its inception.

Payjoin is an on-chain privacy protocol for Bitcoin that breaks the fundamental assumptions made by on-chain analysis companies about user behavior, such as the assumption that one of the unspent transaction outputs (UTXO) generated by a transaction is change returned to the sender. The protocol adds a layer of off-chain coordination that obscures user intent by making the amounts sent and returned ambiguous, thus protecting on-chain privacy without requiring a hard or soft fork of the Bitcoin consensus. When BULL Wallet users buy and sell Bitcoin on-chain through the built-in exchange, transactions will default to using Payjoin, helping buyers passively aggregate UTXOs in their wallets, reducing future Bitcoin miner fees while shrinking the Bitcoin UTXO set size and alleviating fee pressure for all users.

Payjoin transactions are used to protect users from malicious actors attempting to glean their financial habits through on-chain analysis. Since Bitcoin transaction amounts are public, outsiders may infer personal salaries or investment strategies, and as a non-custodial exchange, Bull Bitcoin leaves an on-chain trace for every transaction. In December 2024, BULL Wallet became the world's first wallet to integrate the Payjoin V2 protocol, a project advanced in collaboration with Dan Gould and the Payjoin Dev Kit team, with all related wallet and exchange software being completely free and open-source. Users only need to download BULL Wallet, create a Bull Bitcoin exchange account, and log in through the BULL mobile app, with the rest of the process being automated.