<p>Safety is relative---large payment processors like Coinbase probably have non-block-chain anti-fraud measures.  However, a confirmation (and each additional confirmation after it) reduces the risk of a double spend fraud, so waiting for a certain number of confirmations is an easy and effective anti-fraud measure that doesn't cost you anything.</p>

<p>I don't know for sure what happened to MtGox, but it is true that an unconfirmed transaction can become effectively unspendable if any of its inputs become unavailable---which could happen because a block was created containing a transaction that already spent that input (a double spent) or because the transaction which created that input was added to a block in a mutated form (transaction malleability).</p>

CC BY-SA 3.0
2015-01-13T21:48:22.883Z
2015-01-13T21:48:22.883Z
David A. Harding
<p>I've been running into problems with a high-traffic hot wallet, where a single transaction would lock up any input for a block with the <code>spendzeroconfchange</code> disabled.</p>

<p>Would it be safe for a service like Coinbase to use unconfirmed inputs on average transactions? Would I run into similar issues like MtGox did?</p>

<transactions><bitcoind><unconfirmed-transactions>
How safe is sending out transactions using unconfirmed inputs for a service?
John T
# How safe is sending out transactions using unconfirmed inputs for a service?

(Asked by: username_0 on 2014-10-14)

I've been running into problems with a high-traffic hot wallet, where a single transaction would lock up any input for a block with the `spendzeroconfchange` disabled.

Would it be safe for a service like Coinbase to use unconfirmed inputs on average transactions? Would I run into similar issues like MtGox did?

**Tags:** transactions, bitcoind, unconfirmed-transactions


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## 1 answers

### Answer by username_1 on 2015-01-13. Score: 1

Safety is relative---large payment processors like Coinbase probably have non-block-chain anti-fraud measures. However, a confirmation (and each additional confirmation after it) reduces the risk of a double spend fraud, so waiting for a certain number of confirmations is an easy and effective anti-fraud measure that doesn't cost you anything.

I don't know for sure what happened to MtGox, but it is true that an unconfirmed transaction can become effectively unspendable if any of its inputs become unavailable---which could happen because a block was created containing a transaction that already spent that input (a double spent) or because the transaction which created that input was added to a block in a mutated form (transaction malleability).


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