Using the Coin Control feature is a powerful way to manage your Bitcoin privacy and efficiency. This guide covers the best practices to follow, helping you make informed decisions and avoid common mistakes when selecting your UTXOs.
Label everything
The single most important practice for effective Coin Control is to label your transactions and addresses.
Without labels, your Coin Control panel will just show a long list of addresses and amounts. This makes it very difficult to know the origin of your funds. Labels add essential context, transforming that complex list into a clear overview of your financial history. This dramatically reduces the risk of selecting the wrong UTXOs.
Good labels are descriptive. For example:
- From Kraken (KYC)
- Salary payment 09/2025
- Payment from client X
- Private purchase
You can add a note to a transaction in two ways: by clicking the magnifying glass on a transaction in your history and adding a note in the details view, or by adding a note directly in the Send screen. For more details, see our guide on managing wallet labels.
Separate your UTXO types
The primary reason to label your UTXOs is to keep them separated based on their source. When you create a transaction, all the inputs (the UTXOs you select) are permanently linked together on the blockchain.
For maximum privacy, we recommend that you avoid combining UTXOs from different privacy categories in the same transaction. A good rule of thumb is to not mix UTXOs from KYC (Know Your Customer) sources with UTXOs from private or non-KYC sources. Mixing them can create a permanent link on the blockchain that allows chain analysis firms to connect your private funds to your real-world identity.
Avoid address reuse
For optimal privacy, it's best to use a fresh Bitcoin address for every incoming payment. The BitBoxApp helps you track this by marking any UTXOs from a reused address with an “Address re-used” label in the Coin Control panel.
However, we understand there are situations where address reuse is necessary, such as whitelisting a single withdrawal address on an exchange. In these cases, it is acceptable to reuse an address, but it's important to be aware that this creates a stronger link between those transactions and is a trade-off for convenience.
Consolidate dust wisely
You can use Coin Control to combine multiple small "dust" UTXOs into a single, more useful one. The best time to do this is when Bitcoin network fees are low. Consolidating during periods of high fees can cost you more than the value of the dust itself.
Check your change
When you spend a UTXO and don't use the full amount, the remainder is sent back to you as a new UTXO to a "change address". It's good practice to find this change output in your transaction history and label it appropriately. For example, if you consolidated KYC UTXOs, you could label the resulting change UTXO as Change from KYC consolidation.
Frequently Asked Questions
What happens if I accidentally mix my UTXOs?
Once a transaction is confirmed on the blockchain, the link between the UTXOs you selected is permanent. This is why careful selection and clear labeling are so important before you send. If you do accidentally mix funds, be mindful that this new combined UTXO now carries the history of all the inputs you used.