<p>Yes it can. See this transaction below.</p>
<p><a href="https://blockchair.com/bitcoin/transaction/b345c51064074f5d6c0e11187326567765eb4fa3236ca1be440ccb5745775238" rel="nofollow noreferrer">https://blockchair.com/bitcoin/transaction/b345c51064074f5d6c0e11187326567765eb4fa3236ca1be440ccb5745775238</a></p>

CC BY-SA 4.0
2013-08-19T14:27:04.683Z
2022-07-28T12:28:49.980Z
2022-07-28T12:28:49.980Z
T9b
<p>Yes, and you might want to read up on <a href="https://en.bitcoin.it/wiki/Change" rel="nofollow">handling change</a> as that's one good reason to do so.</p>

CC BY-SA 3.0
2013-08-25T12:26:33.980Z
2014-09-13T17:54:09.843Z
2014-09-13T17:54:09.843Z
John Henry
<p>You can even have a transaction with only 1 input and 1 output, both being the same address</p>

CC BY-SA 3.0
2013-08-26T02:25:23.437Z
2013-08-26T02:25:23.437Z
RentFree
<p>At the protocol level, there is no such thing as "balance of an address". There are individual unspent outputs (like coins in a wallet), which must be individually spent. You can't partially spend an output, but you can split/combine it.</p>

<p>So for example, you have a 70 BTC output assigned to an address, and a 80 BTC output assigned to the same address. Some software will show this as 150 BTC balance of that address, but you still need to know the individual outputs to spend them. If you want to send 100 BTC to someone, you would consume those two outputs in a transaction, and create two new outputs using it, a 100 BTC one (to the recipient) and a 50 BTC one (back to yourself).</p>

<p>Whether you use a new address for that 50 BTC "change" output doesn't matter to the protocol. You can reuse the old one, but will make it obvious to everyone in the world which who was the sender and who was the recipient in the transaction. Using a fresh address improves privacy.</p>

<p>Seen otherwise: reusing the same address may look convenient, as it allows you (and software you use) to more easily distinguish what your balance is, but it does this at the cost of making it obvious to everyone in the world. This hurts Bitcoin's privacy - not just yours, but that of everyone in the system.</p>

CC BY-SA 3.0
2014-08-03T14:43:55.717Z
2014-08-03T14:43:55.717Z
Pieter Wuille
<p>Can a Bitcoin transaction have the same address for input and output, i.e. spend some of the coins that are linked to an address and send the rest back to that same address? Is there some reason why it is imprudent to do so?</p>

<transactions><protocol><change><address-reuse>
Can a Bitcoin transaction have the same address for input and output?
Murch
# Can a Bitcoin transaction have the same address for input and output?

(Asked by: username_0 on 2013-08-19)

Can a Bitcoin transaction have the same address for input and output, i.e. spend some of the coins that are linked to an address and send the rest back to that same address? Is there some reason why it is imprudent to do so?

**Tags:** transactions, protocol, change, address-reuse


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## 4 answers

### Answer by username_4 on 2014-08-03. Score: 17 | Accepted answer

At the protocol level, there is no such thing as "balance of an address". There are individual unspent outputs (like coins in a wallet), which must be individually spent. You can't partially spend an output, but you can split/combine it.

So for example, you have a 70 BTC output assigned to an address, and a 80 BTC output assigned to the same address. Some software will show this as 150 BTC balance of that address, but you still need to know the individual outputs to spend them. If you want to send 100 BTC to someone, you would consume those two outputs in a transaction, and create two new outputs using it, a 100 BTC one (to the recipient) and a 50 BTC one (back to yourself).

Whether you use a new address for that 50 BTC "change" output doesn't matter to the protocol. You can reuse the old one, but will make it obvious to everyone in the world which who was the sender and who was the recipient in the transaction. Using a fresh address improves privacy.

Seen otherwise: reusing the same address may look convenient, as it allows you (and software you use) to more easily distinguish what your balance is, but it does this at the cost of making it obvious to everyone in the world. This hurts Bitcoin's privacy - not just yours, but that of everyone in the system.


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### Answer by username_1 on 2013-08-19. Score: 10

Yes it can. See this transaction below.

<https://blockchair.com/bitcoin/transaction/b345c51064074f5d6c0e11187326567765eb4fa3236ca1be440ccb5745775238>


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### Answer by username_2 on 2013-08-25. Score: 2

Yes, and you might want to read up on [handling change](https://en.bitcoin.it/wiki/Change) as that's one good reason to do so.


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### Answer by username_3 on 2013-08-26. Score: 1

You can even have a transaction with only 1 input and 1 output, both being the same address


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