<p>Transaction ID usually refers to the <a href="https://en.bitcoin.it/wiki/Protocol_specification#Hashes" rel="nofollow">2xSHA256 hash</a> of the transaction serialized as it would have been transferred in the network. This is also the ID as peers <a href="https://en.bitcoin.it/wiki/Protocol_specification#Inventory_Vectors" rel="nofollow">refer to them</a> when broadcasting through the network.</p>

<p>Notice that due to <a href="https://en.bitcoin.it/wiki/Transaction_Malleability" rel="nofollow">transaction malleability</a> a transaction may have multiple IDs.</p>

CC BY-SA 3.0
2014-08-06T19:41:16.390Z
2014-08-06T19:41:16.390Z
cdecker
<p>I have sent a Bitcoin amount to someone who wants the transaction ID. What is this? Is it the hash shown on the LHS of the transaction?</p>

CC BY-SA 3.0
2014-08-06T03:21:23.617Z
What client software are you using?
Nate Eldredge
CC BY-SA 3.0
2014-08-06T03:29:57.873Z
I do not know what you mean by "client software" but for what it is worth I am using the blockchain wallet system.
Graeme
CC BY-SA 3.0
2014-08-06T03:33:57.113Z
Via the website, the mobile app, or something else?
Nate Eldredge
CC BY-SA 3.0
2014-08-06T03:42:43.313Z
via the website
Graeme
<blockchain.info><transaction-id>
What is the transaction ID?
Graeme
# What is the transaction ID?

(Asked by: username_0 on 2014-08-06)

I have sent a Bitcoin amount to someone who wants the transaction ID. What is this? Is it the hash shown on the LHS of the transaction?

**Tags:** blockchain.info, transaction-id

> **Comments:**
> **username_1**: What client software are you using?  
> **username_0**: I do not know what you mean by "client software" but for what it is worth I am using the blockchain wallet system.  
> **username_1**: Via the website, the mobile app, or something else?  
> **username_0**: via the website  

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## 1 answers

### Answer by username_2 on 2014-08-06. Score: 4

Transaction ID usually refers to the [2xSHA256 hash](https://en.bitcoin.it/wiki/Protocol_specification#Hashes) of the transaction serialized as it would have been transferred in the network. This is also the ID as peers [refer to them](https://en.bitcoin.it/wiki/Protocol_specification#Inventory_Vectors) when broadcasting through the network.

Notice that due to [transaction malleability](https://en.bitcoin.it/wiki/Transaction_Malleability) a transaction may have multiple IDs.


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