Why does my address change after a transaction

Not sure if this is the right place to post this, but if it’s not, just tell me where to go and I’ll move it. So I set up a wallet with BlueWallet a while back and just realized that my address keeps changing every time I use it. I didn’t think much of it at first, but it’s happened a few times now. I checked the app and saw a bunch of addresses listed as "used" next to those I’ve received funds to, and others marked as "receive" that haven’t been used yet. I’ve got a few questions: Why does my address change after each transaction? Will I still get any funds sent to the addresses I've already used? Do all these addresses have their own unique private keys? Is there a way to stop this from happening? Oh, and I imported the wallet into Trustwallet using the key phrases I got when I first created it, and it only shows the first address on the list, which is marked as "used" in BlueWallet. I really need some clarity on this.

The change of address is good and for security reasons because using one same address does not enhance your security and privacy and that is why blue wallet is doing that for you. Of course yes, there are upto 20 addresses or more in your wallet that belongs to you and if funds are sent to any of them, you will receive your funds. I have used one same address to receive funds over and over again. Since your wallet only have one seed phrase, all those addresses have a private key which was generated from your wallet seed phrase There is no need to worry about that because your coins are safe in those addresses in your wallet, if you keep your seed phrase safe from third-party. It is showing used because you have used that address to receive funds, but it does not mean anything.

Privacy. Yes. Yes. But they're all derived from the same seed phrase (probably 12 words, you should have a safe backup). Why would you want that? You shouldn't mess with private keys unless you know exactly what you're doing.

There's nothing wrong mate, it's called a Hierarchical deterministic wallet (HD). it's a feature now designed in modern wallets. To increase privacy. This process involves using your seed phrase to generate multiple private keys and corresponding public addresses. This way, your wallet gets different child address and privatekeys for each of them. These keys are created from the same parent key or seed. Once the current address receives a transaction, a new address is generated and provided to you by your wallet. The whole process is done automatically. All child address, can receive funds separately, and will be seen or accessed from your seed phrase.

An example is if you give the address to someone to be receiving payment just like receiving payment from signature campaign on this forum. If you used the first address, the second address will be the one that you will see that you can copy from the receive tab. But if you continue to use the first address for payment, the second address will not change until you use it to receive payment also. This is nothing to be concerned about. If you need privacy, you will need to give provide different addresses for different transactions but what to do to have privacy is still more than this. What he meant is that he imported Trustwallet seed phrase on Bluewallet. You can not see your keys on Trustwallet. Trustwallet is not a recommended wallet if it is about bitcoin and it is close source. I will prefer to generate new seed phrase on Bluewallet wallet instead.

1. Privacy sake 2. As Long as you have access to the seed phrase everything generated on that seed phrase will still be available. 3. Each address have its unique private key called the child private key which is generated from the master private key which also comes from the seed phrase you imported so yes there is each child private key for each address. 4. You can stop it manually by copying the same address you used before but it defeats privacy Trustwallet actually generates an HD wallet keys like the rest wallets but only displays one address whereas BlueWallet actually generates new addresses each time you used a new one with Atleast 20 free unused receivers address available. So it’s nothing new. It will be worth mentioning also that your seed phrase from trustwallet is not good for security purposes to use as it is from a closed source wallet. So I will advice you actually generate a new wallet on BlueWallet instead and send funds there.

That's even worse. Sharing the same seed with two wallets increases the chance of one of them being compromised.

The change of addresses in a wallet is a privacy orientated wallet that increases the chance of your privacy when carrying out transactions. it changes to keep you address unrelated except you decides to like link them together. If you're a privacy oriented person you should enjoy your addresses changing frequently. Of course their is no chance of losing your money if it's sent to one of the used addresses and perhaps when you are spending if you receive from several addresses you can still spend them together but it's not advisable because it negates  the the essence of the privacy which the wallet tries to preserve. Yes, you use your 12/24 words seed phrase to generate private keys for each address but you more be careful while doing that. Why do you want to stop it? it's not reasonable, if you don't care about your privacy you can use other wallets that doesn't support that privacy protocols.

That is the reason why I asked the question here. By showing that used, I thought I can not longer make use of that address and probably lose coins sent there but I'm cleared now. Thank you. Oh...I have the phrases for the main wallet but is there any necessity for me to write out each address key again? No, I was just being scared thinking I will not receive coins sent to other address that I normally use but everything is cleared to me now. Thank you. What I mean is that I imported the seed phrase generated from BlueWallet into Trustwallet to see whether the address will change but it did not. The first address on the list in BlueWallet is what appeared in Trustwallet and it's already used in BlueWallet. I did not generate any seed from Trustwallet. Is there any problem importing address into Trustwallet?

Aside from privacy, you can label each address where you have easier time to find out how you receive/send Bitcoin. Their documentation doesn't mention any way to do that[1]. But if you really want to use same address, head to address tab and copy older address. [1] https://bluewallet.io/docs/

Your seed phrase (+ passphrase, if there's any) is all you need to generate your private keys and you don't need to backup the individual private keys. Yes, with importing the same seed phrase in a different software, you open a new attack vector for hackers and you decrease your security. Also note that trustwallet is close-source and you should never use it.

For your privacy. Yes, you can receive bitcoins sent to your previously used public addresses. Because these addresses all belong to your wallet. Yes, one public address is taken from one private key but with a hierarchical deterministic (HD), you can start from a wallet seed to create a tree of keys. You can use any of these keys. https://github.com/bitcoinbook/bitcoinbook/blob/develop/ch05_wallets.adoc https://learnmeabitcoin.com/technical/keys/hd-wallets/ Why do you need to stop a good feature for your privacy. What is Bitcoin change address?

To add to this, keep in mind once you put your seed phrase into any closed source wallet it's not like deleting the wallet makes it safe again. You do not know what trustwallet did with your seed. If it's any substantial amount of money create a new wallet (seed) in blue wallet and transfer the funds to that one. -Dave

If the amount of the coins is not small, it is good to look for wallet that has better security just like Electrum on an airgapped device or cold hardware wallet like Foundation Passport. This is not new to you but maybe this might be helpful to knowngunman.