Manual coin selection in the Blockstream app lets you choose exactly which coins to spend when you send bitcoin. Each coin (also called a UTXO) is an amount you received in a past transaction. By default, the app picks coins for you; manual selection gives you control over which ones go into a transaction.
Choosing your coins helps in two ways. It protects your privacy, because you can avoid combining coins from unrelated sources in one transaction, which would link them on the blockchain. It can also lower fees, because spending one large coin costs less than spending many small ones.
Note: Manual coin selection is available in the Android app (version 5.6.0 and later) and the desktop app for Bitcoin and Liquid Bitcoin (LBTC) accounts. It is not available in the iOS app, or for Lightning accounts, AMP accounts, or Liquid assets such as USDT.
Select Coins When Sending
1.
Start a send as usual: select Send, then enter or scan the recipient address and the amount.
2.
Open the coin list by tapping Select Your Coins on mobile, or by clicking Manual coin selection on desktop.
3.
Select each coin you want to spend. The count of selected coins and their total amount update as you go. Mobile: a check mark appears on each selected coin; use Select all or Unselect all to change every coin at once. Desktop: the screen also shows the maximum you can send with the current selection.
4.
Select Confirm Coin Selection.
5.
Back on the send screen, the app shows how many coins are selected. Mobile: tap Change to adjust the selection. Desktop: click the edit icon to adjust the selection, or the x icon to clear it. Then continue to review and confirm the transaction.
The selected coins must cover the amount plus the network fee. If they do not, add more coins before confirming.
Read the Coin List
Each coin in the list shows its amount, its fiat value, and its outpoint (the transaction ID and output index it came from). Some coins carry a label.
A Dust label marks a coin worth less than 1,092 satoshis, which costs more in fees to spend than it is worth. Dust can be change your own wallet created, or tiny amounts sent by third parties trying to spam or track your wallet.
A 2FA Expired label appears in a 2FA-protected account on a coin whose two-factor protection has expired because it has not moved for a long time. See The upgrade from nLockTime to CheckSequenceVerify.
Use Filters to show only dust or only 2FA-expired coins. On mobile, the filter button appears only when your account holds coins of those types.
On desktop, you can also browse every coin in an account outside the send flow: open the Transactions tab and select Coins.
Note: Spending dust alongside your other coins links them together on the blockchain. If you want to keep dust separate, leave it unselected.