What is a bitcoin transaction fee and why am I being charged one?

Transaction fees are required for miners to process a transaction on the bitcoin network.

Why do I need to pay a fee?

To send any transaction on the bitcoin network, you must include a transaction fee, which bitcoin miners collect for processing your transaction. Those fees go to bitcoin miners. If you tried to send a transaction without a fee, miners would have no reason to include your transaction in the blocks they add to the blockchain. Unchained does not collect any part of the transaction fee. 

What is a “fee rate” and why do they matter?

Many people worldwide are sending bitcoin transactions, but only a limited number of those transactions can be processed by miners at a time. Miners are incentivized to choose the transactions that pay them the highest fee rate, measured in sats/vByte. The fee rate you choose will make a big difference in how long your transaction will take to be processed, also called confirmed.

  • If you use a fee rate that is the same or higher than the overall market, miners are more likely to select your transaction, which can cause a quick confirmation time.
  • If you use a fee rate that is lower than the overall market, miners are less likely to select your transaction. Confirmation could take hours, days, or even weeks.

How high should I set my fee?

To make things easy for you at Unchained, we estimate the required fees when you withdraw. You have three options. If your chosen fee rate is below the low priority fee rate, we will caution you about a probable confirmation delay.

  • High priority: estimated to be processed within an hour.
  • Low priority: estimated to be processed within 24 hours.
  • Custom: Set a custom fee rate. You can view current fee estimates on mempool.space.

Caution: When you first create a withdrawal transaction, you set the fee rate before signing. However, if you don’t sign and broadcast your transaction right away, the current fee rate can change. If you need time to gather signatures and approvals, make sure you review the fee rate information before broadcasting your transaction.

How long will it take to confirm my transaction?

Miners add blocks to the blockchain about once every 10 minutes on average, but there is always an element of randomness—sometimes there are several hours between blocks. Unchained has no control over this. You can see see an estimate by looking up your transaction ID on mempool.space.

Caution: Both high and low-priority time estimates are only estimates and your withdrawal could sometimes take much longer. Unchained's fee estimation is provided by mempool.space

Help! I set the fee too low, and my transaction is stuck!

We have a separate guide on resolving a stuck transaction by increasing the fee paid. You can always contact our Client Services team with questions.