Bitcoin fees are paid to miners for including a transaction in a block. They are priced by how much block space the transaction uses, not by how much bitcoin it moves, so sending 1,000 BTC can cost the same as sending 0.01 BTC. For a corporate treasury, network fees are usually small relative to trade size, but they are variable and can spike, so they need a simple budget and policy.
This article covers network fees only. Trading spreads and provider charges are a separate subject, covered in best execution for corporate Bitcoin trades.
How Bitcoin fees are calculated
Each block has a limited capacity. Transactions compete for that space, and miners generally pick those paying the most per unit of space.
The unit is the virtual byte (vbyte). Fees are quoted as satoshis per vbyte (sat/vB). The total fee is:
Fee = transaction size in vbytes × fee rate in sat/vB
A satoshi is one hundred-millionth of a bitcoin, the smallest unit the ledger records.
Size depends on structure, not value:
- Number of inputs. Each unspent output being spent adds size. A wallet with many small receipts costs more to spend from.
- Number of outputs. Each recipient, plus change, adds size.
- Address type. Newer formats such as native SegWit and Taproot are more compact. See what is a Bitcoin address.
- Custody model. Multisig transactions carry several signatures and are larger than single-signature ones, though Taproot narrows the gap.
Why fees go up and down
There is no fixed price. Fees reflect demand for block space at a given moment. Pending transactions wait in the mempool, and the fee rate needed to get into the next block rises when the queue is long.
Typical drivers of fee spikes include sharp market moves, when many users move funds at once, and periods of heavy non-financial use of block space. Quiet periods, often weekends, tend to be cheaper, though this is a tendency rather than a rule.
Over the long term, fees also matter to the network's security. As the block subsidy halves every four years, fees are expected to make up a larger share of miners' income. We discuss this in how mining secures the network.
Speed versus cost
A company chooses its fee rate when it sends a transaction. The choice is a trade-off.
| Urgency | Approach | Typical use |
|---|---|---|
| Next block | Pay the prevailing high-priority rate | Settlement deadlines, collateral calls |
| Within a few hours | Pay a moderate rate | Routine transfers to custody |
| No deadline | Pay a low rate and wait | Consolidation, internal moves |
If a transaction is stuck, two tools can speed it up:
- Replace-by-fee (RBF). The sender replaces the transaction with a version paying a higher fee. The wallet must flag it as replaceable when first sent.
- Child-pays-for-parent (CPFP). The recipient, or the sender via change, spends the unconfirmed output with a high fee, pulling both through together.
Both should be covered in operating procedures, with clear authority for who may use them.
How to budget for Bitcoin fees
For most corporate treasuries, network fees are a minor cost line. The aim is predictability, not optimisation to the last satoshi.
A practical budget approach:
- Count expected transactions. Purchases delivered to custody, internal transfers, rebalancing and any sales.
- Estimate size. Ask the custodian for typical vbyte size of a transfer in your wallet set-up.
- Apply a range of fee rates. Model a calm rate, a busy rate and a stressed rate.
- Add consolidation. Plan periodic housekeeping transactions to merge small outputs.
A simple illustration, using round numbers rather than market data: a company expects 40 transfers a year, each around 250 vbytes in its custody set-up. At a calm rate of 5 sat/vB, the annual cost is 50,000 satoshis, or 0.0005 BTC. At a stressed rate of 200 sat/vB, the same activity costs 2,000,000 satoshis, or 0.02 BTC. The range is wide, but even the stressed case is usually small against the value moved. The point of the exercise is to know the range in advance and to agree who may approve a transfer at the top end of it.
Fees are generally treated as a cost of the transaction for accounting purposes, but the right treatment depends on the framework and the facts. See accounting for Bitcoin trading and network costs, and take your own accounting and tax advice.
Controls that keep fees in check
- Fee ceilings. The custody platform rejects transactions above a set sat/vB rate unless an additional approver signs off.
- Batching. Where several payments are due, one transaction with several outputs is cheaper than several separate ones.
- Consolidation windows. Merge small outputs when fees are low, so that urgent spends later are cheap.
- Receipt hygiene. Ask counterparties to deliver large purchases in fewer, larger transfers rather than many small ones.
- Monitoring. Record the fee and fee rate for every transaction in the reconciliation log.
Ask your custodian to set a default fee ceiling and a documented override process. It prevents one rushed transfer during a fee spike from costing many times your normal network spend.
Who pays the fee in a trade
In an OTC purchase, the provider normally pays the network fee for delivering bitcoin to your address, and may build it into the price. On a sale, you usually pay to send bitcoin to the provider. Confirm this in the trade terms and check that it appears in the execution report.
How The Bitcoin World helps
We help finance teams set a network fee policy, including ceilings, batching and consolidation, as part of their custody and execution design. Transactions are signed and broadcast by licensed third-party custodians or under the company's own controls. Learn more about our corporate treasury work.