Bitcoin Forum

Hello! My transaction sent to two wallets, but I indicated only one wallet in sending,
Should I panic?

The other address is most likely your change address. It's basically the change of the transaction being sent to one of your addresses.

The way Bitcoin works is that you spend the inputs you receive like bills. If you receive a transaction of 1 BTC, you have an input of 1 BTC (image this like a bill of 1 BTC). If you then try to send 0.3 BTC to someone, you will create 2 outputs from that 1 BTC input: one of 0.3 BTC to the address you are sending to, and one of 0.7 BTC (the change) back to one of your addresses. And this is all done automatically by most wallets.

You can read more about it here:
https://en.bitcoin.it/wiki/Change
https://themoneymongers.com/bitcoin-change-address/

Would you mind sharing the transaction id?

There is no need to panic at all.
If you were trying to send part of the amount to the address you provided, then that means the change was sent to a new address(Change address) which is also still part of your account. You can verify by refreshing or re-syncing your wallet. You should be able to see the remaining BTC and you can also be able to spend it any time.

Actually you sent transaction to single address, not wallet. But btc has been split into 2 address. You may noticed your wallet balance is accurate. Like you had 2 btc and you sent 1 btc to other address, now you should have less than 1 btc (will exclude fee from remaining 1 btc depend on how much fee have you used). So you don't need to be panice.

I have wrote about it just few days back. What is "Change" address on bitcoin wallet ? read to know ! (https://bitcointalk.org/index.php?topic=5190841.0), so you will know what happened exactly with your btc.

OP, if your balance shows the correct amount right now, you should be alright. Read the posts others wrote before me for the complete answer.

However, just as a prevention note:

I remember change addresses didn't exist on paper wallets and you could lose your funds in such an easy manner this way (having a paper wallet loaded with funds and not spending it all). I guess this still happens and there hasn't been any "fix" as a Bitcoin update for prevention, right? So OP, if you ever send your funds to a paper wallet, make sure you spend ALL of it when you import your paper wallet back in.

If you have 1BTC on paper, you import the paper privkey into a wallet and you only spend a part of it, the rest of the funds would go to another address (called a "change" address, as others above me said) which you won't have the access to. A private key only imports a single address, not a wallet. Or am I wrong?

I'm trying to help, please someone tell me if I'm wrong about anything :D

With most wallet configurations, importing an address means that the change would go back to the change address. Spending all the funds in a paper wallet is better for security as the paper wallet would've been exposed to the internet. The more serious repercussion with that is the loss of privacy; it would be fairly easy to tell which is the intended address and which is the change, thereby resulting in a decrease in privacy.

Why would the paper wallet be exposed to the Internet? Because you introduce the private key while your wallet is connected to the Internet?

Generally, when the private key is imported into a wallet which has been connected to the Internet, it is not considered airgapped anymore; it is possible for the private key to have been exposed to a third party via the Internet.

Of course, exceptions exist and your wallet would probably still be safe if you employ the use of an offline computer to sign the transaction before transferring it to an online computer to broadcast it. But that would be too much of a hassle and it is generally not recommended to reuse the paper wallet.

I wouldn't call that too much of a hassle at all. In fact, I will only use a paper wallet by importing it on to an airgapped machine. If you have a paper wallet you should have access to a properly airgapped machine, because paper wallets should only be generated on an airgapped machine. If your paper wallet was generated on an internet-connected device, then it's not really secure.

The whole point of paper wallets are to be proper cold wallets - safe and secure precisely because they have never touched the internet. If you generate one or import one on a live machine, then you are defeating their very purpose.

we don't have access to your wallet and since you haven't provided any info we can only guess. so post the transaction id, wallet software name and version, intended recipient's address and amount.

Yes, paper wallet is just one address for cold long-term storage. Most of the "modern" wallets (online/desktop/hardware) are now designed as HD wallets, so they generate many bitcoin addresses and change addresses based on one master private key (256bit number, i.e secret seed words). HD wallets use "change" addresses for inbuilt HD wallet addresses, but not for "imported" addresses by default. It is always recomended for unexperienced users to "transfer"/import the whole balance from paper wallet to HD wallet for subsequent transactions.

We do not no any other details how OP created the transaction: was it made manually? was it sent from paper wallet or HD wallet? was the addresses imported to some online exchange? etc.

As it has been already written above, all the outputs from address includes the inputs as well. The difference between inputs and outputs is the transaction fee (which is received by the mainer together with the bock reward). That's why, the worst case for OP in this situation is that the transaction difference was considered as a transaction fee, and went to miner. In this situation OP could write the message to miner, explain the mistake and ask to return the funds.

By the way, "change" address could be also the same as the sending address. There are a lot transactions with the same change address, and the remaining difference returns to the initial address. But it is not recomended of course. The modern way is to use "own change" address which is generated within the same wallet.

Transaction scheme (1BTC = 0.3BTC + 0.699BTC + 0.001BTC):

So, if the transaction was made manually, and the change address was not specified, so the remaining input (in the case above 1BTC - 0.3BTC = 0.7BTC) should be considered as the transaction fee, and went to miner's address together with the reward for calculated block (includes your transaction as well).


Share the transaction ID. If you do not want to share the transaction, just check if you have the access to the 2nd wallet. If yes - no panic. If no, and the transferred amount to that wallet significant for you - you can panic.