When you send Bitcoin, you may notice that the original address in your wallet appears empty afterward, even if you only transferred part of your balance. There is no need to worry. Your remaining funds have not been lost. Instead, they have been sent to a change address, which is a newly generated address controlled by your wallet.
How It Works
Bitcoin follows the UTXO (Unspent Transaction Output) model. In this system, each transaction uses one or more previous outputs in full and then creates new outputs.
If the total input amount is larger than the amount you want to send, your wallet will automatically do two things:
Send the requested amount to the recipient.
Return the remaining balance, after deducting network fees, to a change address managed internally by your wallet.
For example, if your wallet contains 1 BTC and you send 0.3 BTC, the wallet will create a transaction that:
Spends the full 1 BTC input
Sends 0.3 BTC to the recipient
Returns approximately 0.7 BTC minus fees to a newly generated change address
Why Use Change Addresses?
Change addresses are mainly used to improve privacy.
They make it more difficult for outside observers analyzing the blockchain to determine which output was the actual payment and which one was the returned change. This helps reduce the chances of all your transactions being easily linked together.
That said, change addresses do not make Bitcoin fully anonymous. In certain situations, such as when different address formats are involved, the change output may still be identifiable.
Change addresses were not included in Bitcoin’s original 2008 release. They were introduced by Satoshi Nakamoto in 2010 as the protocol evolved, with the goal of improving both privacy and usability.
Key Takeaways
Change addresses are created automatically by your wallet, so no manual management is required.
They are part of the same wallet and are derived from your seed phrase.
They improve privacy, but they do not provide complete anonymity.
What Is the “Fresh Address” Feature and How Do You Use It?
The “Fresh Address” feature was introduced in UKey App version 5.16.0. It allows the wallet to generate a completely new and unused BTC address. Each time you receive funds, the wallet creates a new address that has never been used before and is not linked to previous transactions.
By design, blockchain systems are not privacy-oriented, and all transactions are publicly recorded. Both sender and receiver addresses can be viewed through blockchain explorers. If you continue using the same address to receive funds, the full transaction history of that address can be exposed.
To improve privacy and security, once this feature is enabled, your wallet will automatically generate a new receiving address for every incoming BTC transaction. This newly generated address is called a “Fresh Address.”
To enable this feature, go to Settings → Wallet and switch it on. It is enabled by default.
2. After switching to the BTC mainnet, tap Receive, and you will see the “Used addresses” option.