Bitcoin Forum

So I have started actually using bitcoins recently, have been a saver/hodler for 2 years.
The take-away express in the Netherlands lets you order food in bitcoin with zero fees (can save you some 10%).
So last time I noticed that my bitcoin mobile wallet (bitwallet) was empty so I bought some 20 euros of bitcoins online.
After the buy, my wallet had me wait for 3 confirmations (ca 30 min) before I could send out 10 euro worth of bitcoins.
I know that the takeway takes 0-conform transactions, or at least I get a sms-confirm directly, so I pressume as much.

So why is my wallet waiting for 3 comfirms on a small amount? Also are there any guidelines wallet-software could/should follow for confirms?
How does this work at the btc protocol? At which point can an output be used as an input ? After how many confirmations of the output ?

They wait for confirmations to ensure it can be successfully spend.


No.


You can use an output even if transaction has no confirmations. There is no special rule. Wallets usually wait for few comfirmations to ensure it can be successfully spend.

The Bitcoins you receive may not reach your wallet if transaction is dropped later due to lack of fees or if there is a double spend(low chance). So the transaction you spend will be invalid. To ensure this won't happen, wallet usually wait for few confirmations.

Thanks for answering.
I will experiment with a few other wallets, I think required confirmations should be adjusted to spending amount.
3 confirmations waiting time can be very long when you are hungry ;-)

The required confirmations depend on the type of thing you buy/sell. For small payments 3 confirmations is fine. You wouldn't sell your car with one confirmation.

IMHO no. Number of confirmations required depends on the person who you deal with. Some people is fine proceeding with 1 confirmation, some wants 2, some wants 6 etc...  Some exchanges require Bitcoin deposit to have 6 confirmation, some only require 3 confirmations regardless of the amount.