1. How To Get A Bitcoin Wallet Address
2. Can I Change My Bitcoin Wallet Address
3. How To Change Your Bitcoin Wallet Address
4. How To Have A Bitcoin Wallet Address

The change is not available to spend until the bitcoin transaction gets confirmed on the bitcoin network (funds get delivered to the intended address). Consider the example of taking a $20 bill out of your wallet to pay for a $5 cup of coffee. That wallet downloaded and I use my seed / key to activate the wallet. All coins there fine as of 30 hours later. I've read about the bitcoin electrum phishing attacks, but those seem to trick you into going to a different website and downloading a fake client. Whereas my bug seemed to be the wallet software itself trying to update the app. Literally speaking. There is no way to “update” a BTC address. Bitcoin addresses are derived from a private key (think of it as a password).

When the output of a transaction is used as the input of another transaction, it must be spent in its entirety. Sometimes the coin value of the output is higher than what the user wishes to pay. In this case, the client generates a new Bitcoin address, and sends the difference back to this address. This is known as change.

Say you want to buy a candy bar ($1) from a store. You open your wallet (fiat wallet) and inside there is a single $20 bill. What is the min amount you can pay? It isn't $1; you can't rip up 1/20th of the bill and give it to the cashier. You need to pay $20 and since you only owe $1, the cashier gives you back $19. Now in fiat nobody except the central bank can make new bills so bills are in fixed denominations and thus your fiat transaction may look something like the following.

• Inputs:
  • $20 bill

• Outputs:
  • $1 bill to cashier
  • $10 bill to you
  • $5 bill to you
  • $1 bill to you
  • $1 bill to you
  • $1 bill to you
  • $1 bill to you

We do it everyday so it becomes instinctive but if you break it down that is what is happening. Now lets imagine for a second that some system existed which allowed the cashier (or anyone) to securely destroy any authentic fiat money (bills) and print replacements in arbitrary amounts (not just $10s and $20s but $18.94537208 if you wanted to), while preventing double spending, counterfeiting, and ensuring that at all times the amount of money created is exactly the same as the amount of money destroyed. In that case your transaction may look like this:

• Inputs:
  • $20 bill - destroyed
• Outputs:
  • $1 newly created bill to cashier
  • $19 newly created bill to you

That is exactly how bitcoin works. Except instead of bills we call the elements inputs and outputs. When you 'spend' bitcoins (create a transaction) you must use the entire value of an unspent output (of a prior transaction) and make it the input for a new transaction. Your wallet hides this somewhat by continually looking for unspent outputs and adding up their total value. So when your wallet says you have 130 BTC it simply means the sum of all your unspent outputs total 130 BTC. Just like a fiat wallet the value comes from one or more discrete bills/outputs.

How To Get A Bitcoin Wallet Address

Take the case of the transaction 0a1c0b1ec0ac55a45b1555202daf2e08419648096f5bcc4267898d420dffef87, a 10.89 BTC previously unspent output was spent by the client. 10 BTC was the payment amount, and 0.89 BTC was the amount of change returned. The client can't spend just 10.00 BTC out of a 10.89 BTC payment anymore than a person can spend $1 out of a $20 bill. The entire 10.89 BTC unspent output became the input of this new transaction and in the process produced are two new unspent outputs which have a combined value of 10.89 BTC. The 10.89 BTC is now 'spent' and effectively destroyed because the network will prevent it from ever being spent again. Those unspent outputs can now become inputs for future transactions.

In this transaction, the fee is 0 but if there was a tx fee paid it would be the difference between the inputs and the outputs. (i.e. 10.89 BTC input and a 10.88 BTC output = 0.01 BTC fee).

The wallet file contains the private keys for change addresses, and they can receive and send coins normally. However, the GUI in the default client does not display them in the address book, therefore a recommendation is to backup wallet.dat every 50 transactions.

See Also

Your Samourai Wallet contains an infinite amount of bitcoin addresses that get used once and then are archived. These archived addresses are never discarded, but they are not used again to protect your privacy and security.

Can I Change My Bitcoin Wallet Address

This means your bitcoin address will change all the time, this is not cause for alarm, consider your addresses as 'one-time-use' and disposable.

Step 1 - The receive screen

To get your latest bitcoin address press the blue '+' button on the bottom right of the main balance and transactions screen. Then press the green 'Receive' button to open the Receive screen.

How To Change Your Bitcoin Wallet Address

Step 2 - Share your address

How To Have A Bitcoin Wallet Address

Samourai Wallet will display a QR code of your latest bitcoin address. Underneath the QR code is the actual address text. You can show this QR code if you are in transacting in person or you can share the address and QR code manually.

• To copy the address to clipboard: Tap the address text and press 'YES'
• To share the QR code image: Tap the share icon in the toolbar

By default, your Samourai wallet will generate bech32 or 'Native Segwit' addresses (beginning with 'bc1'). If you are sending to your Samourai wallet using a service that does not yet support Native Segwit addresses, you can also obtain addresses in Segwit Compatibility and Legacy formats, via the Advanced gearbox icon on the Receive screen.