<p>The current bitcoin system does not allow to create a block with two coinbase transactions. 
The rules are <a href="https://en.bitcoin.it/wiki/Protocol_rules#.22block.22_messages" rel="nofollow noreferrer">described here</a>. 
So a player against the system would need to craft such a block manually, which would get rejected, and eventually the node would get banned.</p>

<p>Hint: as his is a basic question of how bitcoin works, I recommend to read the technical articles on bitcoin.org, as well as the article on protocol specification in the link. And on top Andreas‘ book „Mastering Bitcoin“ gives a deep insight into the bitcoin world. It is also online available, in many languages. Highly recommended!</p>

CC BY-SA 3.0
2018-03-23T08:40:44.910Z
2018-03-23T08:40:44.910Z
pebwindkraft
<p><strong>Coinbase Transactoin</strong> is created after new block is minned in blockchain.
Its the first transaction happen in any block and the transaction is minning reward(12.5 btc+fee) as per now.  When new block is minned particular amount of bitcoin is generated as minning reward and to make those btc come in existance it need to be assigned to some address. That address is generated within the block and minning reward is stored on that address which is known as coinbase transaction.</p>

CC BY-SA 3.0
2018-03-23T12:48:56.350Z
The address the coinbase coins are sent to does not "need to be generated in the block". It can be any valid bitcoin address, including a previously used one.
Raghav Sood
CC BY-SA 3.0
2018-03-24T22:02:07.380Z
Any valid address doesnt men "any valid address will work", you should have access to the pvt key of the address, so for that obviusly the address has to be generated and ones address is generated and you have access to its pvt key you can use the same address multiple times as well
Parishilan Rayamajhi
CC BY-SA 3.0
2018-03-24T22:10:10.730Z
You can absolutely send the coins to an address for which no private key is known. You don't need access to the private key to send coins to it.
Raghav Sood
CC BY-SA 3.0
2018-03-24T22:11:53.440Z
ohhh wow i didnt know this, how can we do that i am looking forward to try it,any reference?
Parishilan Rayamajhi
CC BY-SA 3.0
2018-03-24T22:17:54.483Z
It's known as "burning" coins. Essentially, you can send them to a Bitcoin address that you provably don't have the private key for. One such example is [1CounterpartyXXXXXXXXXXXXXXXUWLpVr](https://blockchain.info/address/1CounterpartyXXXXXXXXXXXXXXXUWLpVr), which was used for the initial counterparty burn. You can read up on https://en.bitcoin.it/wiki/Proof_of_burn for why burning is a thing
Raghav Sood
CC BY-SA 3.0
2018-03-23T08:47:06.447Z
2018-03-23T08:47:06.447Z
Parishilan Rayamajhi
<p>How can a coinbase transaction be created and what would happen if there was more than one coinbase transaction in a block?</p>

<transactions><block>
How can coinbase transactions be created?
Errol
# How can coinbase transactions be created?

(Asked by: username_0 on 2018-03-23)

How can a coinbase transaction be created and what would happen if there was more than one coinbase transaction in a block?

**Tags:** transactions, block


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## 2 answers

### Answer by username_1 on 2018-03-23. Score: 4

The current bitcoin system does not allow to create a block with two coinbase transactions.
The rules are [described here](https://en.bitcoin.it/wiki/Protocol_rules#.22block.22_messages).
So a player against the system would need to craft such a block manually, which would get rejected, and eventually the node would get banned.

Hint: as his is a basic question of how bitcoin works, I recommend to read the technical articles on bitcoin.org, as well as the article on protocol specification in the link. And on top Andreas‘ book „Mastering Bitcoin“ gives a deep insight into the bitcoin world. It is also online available, in many languages. Highly recommended!


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### Answer by username_2 on 2018-03-23. Score: 0

**Coinbase Transactoin** is created after new block is minned in blockchain.
Its the first transaction happen in any block and the transaction is minning reward(12.5 btc+fee) as per now. When new block is minned particular amount of bitcoin is generated as minning reward and to make those btc come in existance it need to be assigned to some address. That address is generated within the block and minning reward is stored on that address which is known as coinbase transaction.

> **Comments:**
> **username_3**: The address the coinbase coins are sent to does not "need to be generated in the block". It can be any valid bitcoin address, including a previously used one.  
> **username_2**: Any valid address doesnt men "any valid address will work", you should have access to the pvt key of the address, so for that obviusly the address has to be generated and ones address is generated and you have access to its pvt key you can use the same address multiple times as well  
> **username_3**: You can absolutely send the coins to an address for which no private key is known. You don't need access to the private key to send coins to it.  
> **username_2**: ohhh wow i didnt know this, how can we do that i am looking forward to try it,any reference?  
> **username_3**: It's known as "burning" coins. Essentially, you can send them to a Bitcoin address that you provably don't have the private key for. One such example is [1CounterpartyXXXXXXXXXXXXXXXUWLpVr](https://blockchain.info/address/1CounterpartyXXXXXXXXXXXXXXXUWLpVr), which was used for the initial counterparty burn. You can read up on https://en.bitcoin.it/wiki/Proof_of_burn for why burning is a thing  

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