Understanding Bitcoin Transaction Fees

The only Bitcoin exchange fee is for withdrawing Bitcoin from your HardBlock account to a Bitcoin wallet (can be as low as 99 Sats). We have neither AUD deposit fees nor exchange commission - your exchange operation will be at the rate you see at the top of the page.  

When you send bitcoin out of your HardBlock account (on the Send BTC page), you create an on-chain Bitcoin transaction.

Transacting on the Bitcoin network requires paying a fee to the miners who secure the Bitcoin network and confirm transactions. Bitcoin actually lands in the recipient's wallet when the transaction gets confirmations on the network (is included in the block). 

Important: as soon as you send Bitcoin, it is literally (technically) out of the sender's wallet. The Bitcoin algorithm is designed so that none of the transactions within a network can be reversed, revoked, recalled, or undone in any other way by anyone (but the algorithm, if transaction does not make it to the block as a result of being purged from the mempool - see below). It guarantees the network's stability and integrity. 

When you see a TX ID number for your Bitcoin transaction (which is also displayed in your HardBlock's account on Send BTC page), Bitcoin is out of the wallet in the waiting pool (and there is nothing to do here anymore). But Bitcoin does not arrive in the recipient's wallet until it gets confirmations. It will get those eventually, do not worry, the money is not lost.

HardBlock charges a market rate fee for Bitcoin transactions; we do not aim to make a profit on this fee. Its primary purpose is to cover bitcoin transactional costs.

Standard & Fast Transaction Fees

Choose STANDARD transaction speed  when you prefer a cheaper transaction fee and are less time sensitive. The standard fee is displayed at the top of the HardBlock website.
Depending on Bitcoin network congestion it should generally confirm in the next 3 blocks. One block is usually processed within around 10 minutes, but it could take from 1-2 minutes to potentially an hour.
However, on VERY rare occasions transactions can take over a day to confirm. This is when demand for transactions rises quickly causing a spike in transaction fees. As the congestion reduces, the fee rate drops, and your transaction will be processed.

Choose FAST when speed is your priority. Fast transactions will generally be processed in the next block, which is generally within 10 minutes, but could take up to an hour. Again, on very rare occasions (ie once or twice per year) your transaction could take over a day to confirm.

If you just want the cheapest bitcoin transaction fee check out Bitcoin Auto-Send feature. Find out how you can send bitcoin for only 99 Sats using Auto-Send here.

We recommend using the blockchain visualiser mempool.space to view the current network status.

Technicalities of Bitcoin Transaction Fees

Bitcoin fees are determined by two components:

  1. The fee rate (measured in Satoshis per Virtual Byte or Sat/vB)
  2. The size of the transaction, measured in virtual bytes.

We source our fee rates from mempool.space.

  • STANDARD uses "Medium Priority"
  • FAST uses "High Priority

This screenshot shows how the state of mempool fees at the time of writing this article:

The size of a transaction varies due to several factors including the bitcoin address type and how many inputs are required. For simplicity, we charge a fixed 200 vBytes per transaction.

We multiply 200 by the Medium Priority fee rate from mempool.space plus 0.02 (the additional fractional amount prioritises the transaction above anyone who is just using the Medium Priority fee). 

E.g., if the Medium Priority fee on mempool.space is currently 9 Sat/vB, then our fee will be:

(9 + 0.02) X 200 = 1804 Satoshis (or 0.00001804 bitcoin).

The value of this fee in Australian dollars will vary based on the price of bitcoin. The Australian dollar fee is displayed in brackets next to the transaction fee.

Still need help? Contact Us Contact Us