Transactions fees at this time

[Mysil2]

Since I am new here I figured that I might as well just start a topic here in the newbie-section - even without actually doing many searches at this topic.

I discovered the bitcoin currency a couple of months ago and also started to mine as well. What I wonder is how important transaction fees are at this point. I understand that in the future when block rewards are very small the transaction fee is the actual reward.

The standard transaction fee today if I'm correct is 0.0005 BTC. But if I don't include any fee, would the transaction get picked up in a block as of today?

While I probably would just add the 0.0005 BTC in my first transaction, as that fee is of so little value, this post is just for my curiosity (and for creating my very first topic).

[DeathAndTaxes]

There is no standard tx fee.  Non spam tx can be sent with 0 BTC and will be considered valid.  Miners have the choice of what tx they will include and can exclude tx that have too little (or no) fee, but almost all include all valid (non spam) txs regardless of fee.

About spam.  To protect the network the protocol requires a fee of 0.0005 BTC if the inputs are less than 1 bitcoin day old*.  For example if you received 1 bitcoin and wanted to spent it you would have to wait 1 day to avoid a fee.  If you received 10 bitcoins you would need to wait 1/10th of day.  If you received 0.1 BTC and wanted to spend it you would need to wait 10 days.

If you wait that long (or longer) you can send coins without any fee.  If you want to send it early you need to pay the spam-fee.  Other nodes will declare your tx invalid and refuse to relay it if you don't pay the fee.  The client also needs to be modified to get around the fee.  Since unmodified clients will refuse to relay the tx you run the risk of having the tx in limbo or not seen by recipient if you modify a client to break the spam rules.

The important thing is the spam fee isn't designed to "make money".  You can simply wait (or keep some "old coins" handy) and never pay it.  The spam fee is designed to protect the network from a DOS attack involving massive amounts of tiny transactions.

*technically the limit is in blocks but it is roughly 1 bitcoin day which is slightly easier to remember than  57,600,000 satoshi blocks per byte.

[lando coin]

Thanx for this answer

had this question too thanks for the answer

greetings lando

[z3rohour]

Soo paying a TX fee makes the transaction go through faster.

[DeathAndTaxes]

Soo paying a TX fee makes the transaction go through faster.

Non spam tx can be sent with 0 BTC and will be considered valid.  Miners have the choice of including or excluding tx but almost all include all valid (non spam) txs regardless of fee.

In theory yes and someday that may be true.  Today essentially all miners include 100% of tx in the next block (as long as they are not unpaid spam) even with no fee.  So fee (beyond any anti-spam fee required) doesn't really increase speed.

Over time (as block subsidies decline) bitcoin will move to more of a pay per performance kind of model.  I have started requiring fees for tx I process and hope other miners do the same.  

https://bitcointalk.org/index.php?topic=73941.0

Realistically though since he amount of fee is irrelevant for 99% of hashing power it likely will be a while before fees (or lack of fees) have any meaningful effect on confirmation times.

[noresolution]

I apologize for revisiting this old post but I just sent a transaction for 342BTC and accidentally forgot to include a tx fee. I had literally just sent the coins to that wallet and then resent them to Mt. Gox with no fee. So with that very short amount of time between transactions and no fee, will the network consider it spam?

 It's been 3 hours now and 0 confirmations still. Are they lost forever? Is there anything I can do? Please help! I'm really stressed out about this. Thank you!

[DeathAndTaxes]

A clarification.

Did the client notify you need to include a fee and you bypassed it or did you just not include a fee on a tx you weren't warned requires one?  If the later in time the tx will be considered "old enough" to be included without a fee.

Does the tx show up w/ confirmations in blockchain.info?   If so then it is just an issue with your client.

Without the tx id it isn't possible to speculate more.

[Berlu]

About spam.  To protect the network the protocol requires a fee of 0.0005 BTC if the inputs are less than 1 bitcoin day old*.  For example if you received 1 bitcoin and wanted to spent it you would have to wait 1 day to avoid a fee.  If you received 10 bitcoins you would need to wait 1/10th of day.  If you received 0.1 BTC and wanted to spend it you would need to wait 10 days.

Is this still true? I recently sent small values (3-5 BTC) wth inputs that had only 5-10 confirmations. Since the transactions got confirmed in the next 1-2 blocks, I don't think they were considered as spam.

[kinlo]

As long as you didn't change the source code of your bitcoin client, all spam transactions will be forced by the client to include the fee.

This does mean that you can't do stupid things like not including enough transaction fee unless you change the client.

I like the explanation placed here, but I would like to add a few things:

- In addition to the above rules: bitcoin will only accept "Free" transactions up to a specific size.  If your transaction is bigger, then the fee must be higher.  This is also an anti-spam rule.  Size is the bytes required to represent this transaction: if you have many transactions with low value in your wallet, creating one high value transaction requires combining all those transactions, which causes the transaction to be bigger in size.

- Bitcoin miners will only include free transactions up to a certain size in the block they are mining. If the free part of the block is full, the transaction will not be included and can only be included in a later block.   But if you included a fee, the transaction will be included in the block.   The more data in a block, the higher the fee must be to be included in the block.  So if you set a high fee to your transaction, you are sure the transaction is included in the next block.  If the fee is lower, the chance of it not ending up in the current block increases.

[freewil]

I'm hoping that eventually there will be a simple way to know the fee required via rpc someday before sending it.

[kinlo]

I've heard sipa is working on a generic way to choose your input transactions - this way you can see which transactions to include so you can avoid the spam-rules.

Note that the exact fee is up to you.  If you decide to get a free transaction, it might end up being delayed, and only being payed after several blocks have been mined - if the free part of the block is full you need to wait.