Bitcoin Forum

Does bitcoin charge a transaction fee everytime you send out a payment ?

It's trying to charge me 0.0005 fee for me to send bitcoin to someone. Is this normal ?

every time?  no.  for some payments? yes.

to prevent transaction spam, the bitcoin client does determine whether or not a fee would be required for the transaction to get processed in a timely manner: http://en.bitcoin.it/wiki/Transaction_fees

you can use an earlier client, v0.3.20, for instance, which did not yet have that check and your transaction will go out, it just may get queued and take a long time.

but remember -- 0.0005 btc is an amount under a penny.  you won't find a better deal with any other payment network.

With 3.23 it had me paying .01 every time I would go to send it. I updated to 3.35 beta and now I haven't seen another transaction fee (so far)

I used 0.3.21 which asked for 0.01 transaction fee for every transaction (even sending 0.01).. Just updated to 0.3.23 and hope that is gone.

sorry for reviving an old topic, but what is the situation like in the current client? 0.5.1

will it charge fees? if yes, will i get asked about it even when i use just RPC commands?

yes, even with rpc commands.

and i think now it's 0.001 per transaction, if it determines that your transaction is "spammy"

Fees are optional, but miners might ignore transactions without fees. Especially when the mining reward goes down from 50 BTC to 25.
The net effect for you is that your transaction may take longer time to make it into the block chain.

Except for spam transactions.  If your coins are very young and/or the transaction very small the client will enforce a fee.  You can use a modified client to get around this but many miners will just ignore those spam transactions.

For most transactions no fee is required (currently).

I read that "spammy" is defined by an equation using only BTC and byte values.

Does this mean that if I transfer say 24btc after 6 confirmations my transaction will ALWAYS go through free?

And if so, could a government buy a for them small amount of btc, say 24000, and continually send it to themselves to spam the network?


If this is incorrect; are miners then free to ignore ALL transactions and may in the future choose to do so to save power/cpu/whatever?

Looking at blockchain.info there seems to be about 20-120 kb for only 10-100 transactions, is this sustainable in terms of reasonable fees and bandwidth usage going forward?
I mean I would imagine mastercard/visa/paypal combined have maybe a million transactions per 10 min. or more.

Even with my government attack above or just normal use after a bit more adoption that's up toward 500 kb/10 min

If the miners have to become increasingly specialized, won't this in the end cause BTC to become centralized and thus worthless?


I want bitcoin to succeed, but this worries me.

Your questions about transaction fees have been asked before:
https://bitcointalk.org/index.php?topic=48.msg334#msg334

I don't believe that thread really answers my question, perhaps I should clarify:

1. I have read that a miner with 51% control could stop transactions from happening altogether by not including them in the block, is this correct?

2. Is the inclusion of transactions - fitting some specification - in blocks, part of the bitcoin protocol or up to the miners?

It's up to the miners*. But, afaik, the software provided by bitcoin.org enforces an arbitrary fee policy in order to counter spam, instead of raising spam flags based on data transfer rate - I guess it was easier to implement this way and nobody volunteered to improve it yet. As most miners use the software provided by bitcoin.org, they end up following this fee policy too. So, if you don't respect it, there's a high chance you won't get your transaction included.

*Obviously, it's up to them if transactions are valid. A block containing an invalid transaction is not accepted by the network. Example of invalid tx are double-spends, wrong signatures etc

Correct.  Although transactions will still occur they just won't ever be confirmed.

Technically good miners will still build blocks but given enough time they will always be replaced by blocks mined by the 51% attacker.  If the blocks are all empty then no transactions will remained confirmed for very long (or w/ a high confirmation #).  Temporarily the good miners could get some good luck and pull ahead.   You would see see transactions confirm only to have them reverse to unconfirmed when the attack chain resumes its dominance (pulls back ahead as the longest chain).

The fees are optional. It just that if you are willing to pay the fees, the BTC or blocks will be processed faster.

They are not optional, except that there is one pool (Eligius) that includes some transactions that don't include the mandatory fee for low priority transactions when they mine a block. Their exact rules for what they will include are undisclosed (really small spammy payments still don't get included), and they only mine a block every few hours. Without such a pool that has written a custom version of Bitcoin with different rules, payments not including the fee when the mainline client requests inclusion of one would never be processed.