Encyclopedia Bitcoin basics · Entry 181
Sending all your bitcoin: why Send Max differs from the displayed balance
In this article
At a glance
Key facts
Subtract a fee from spendable inputs
If selected inputs total 100,000 satoshis and the final fee is 1,500, a one-output transaction can deliver 98,500 satoshis. That is an illustrative calculation, not a quoted fee for all send-all transactions.
Additional inputs change transaction size. A wallet with many small outputs can pay a different fee from one spending a single output with the same total value.
Find out what the displayed balance contains
Core’s documented balances distinguish trusted, untrusted pending and immature value, with a separate watch-only category when present. Other interfaces group these differently. Selected outputs may also require signatures or policies that the current device cannot supply.
Funding a PSBT can include information useful to another signer without making the transaction fully authorized. A maximum amount calculated in a watch-only interface still needs the actual signing path.
Check the final recipient amount
A fee-subtraction control and a Send Max button are related accounting ideas, but they are not universal synonyms. Verify whether the wallet selected every available output or only a chosen subset, whether it created change and how much the recipient gets.
If the recipient expects an exact invoice amount, a send-all action may underpay it. Fund the requested output and fee separately when that is what the agreement requires.
Direct answers
Questions people ask
Can I send every satoshi without paying a fee?
A wallet may permit a particular fee choice, but nodes and miners apply their own policies and selection rules. Send Max typically reserves a fee; it does not guarantee that a zero-fee transaction will be relayed or included.
Why is Send Max lower than my wallet balance?
The fee reduces the recipient output, and the display may include pending, immature, watch-only or otherwise unavailable value. Compare the selected inputs and their spending conditions with the balance categories.
Inspect the evidence
The answer and key facts have stable claim links. These records retain the scope and qualification when reused.
Send Max normally asks a wallet to spend selected available funds while leaving enough value for the transaction fee. The recipient therefore receives less than the selected input total. A displayed balance may also include outputs the wallet cannot currently spend or sign for. Read the funded transaction’s recipient amount and fee; the button’s exact selection rules depend on the wallet.
Educational explanation. Product-specific behavior is scoped to the cited documentation, checked 2026-10-02.
Scope: Bitcoin · data through 2026-10-02. Verification: verified · 2026-10-02T19:29:20.637Z.
Link to this claimAccounting: Inputs equal outputs plus fee
Scope: Bitcoin · data through 2026-10-02. Verification: verified · 2026-10-02T19:29:20.637Z.
Link to this claimVisibility: A watch-only balance is not signing authority
Scope: Bitcoin · data through 2026-10-02. Verification: verified · 2026-10-02T19:29:20.637Z.
Link to this claimSelection: The wallet decides which available outputs to include
Scope: Bitcoin · data through 2026-10-02. Verification: verified · 2026-10-02T19:29:20.637Z.
Link to this claimRevision history
- — First publication after primary-source research and separate automated verification.
Source register
Sources and references
Retrieval dates and locators are recorded individually.- TransactionsBitcoin developer documentation
Inputs, outputs, authorization, change, coinbase exceptions and fee accounting.
Locator: Introduction; Spending An Output; P2PKH Script Validation; Multisig; Transaction Fees And Change; Avoiding Key Reuse · Version / scope: Developer guide; historical implementation details require qualification · Retrieved: 2026-10-02T18:53:53.759ZOpen source - getbalances RPCBitcoin Core
Wallet balances are divided by trust and spendability-related categories.
Locator: Result: mine, watchonly, trusted, untrusted_pending, immature · Version / scope: Bitcoin Core 29.0 RPC reference; not a recommendation to install an old release · Retrieved: 2026-10-02T18:53:55.000ZOpen source - walletcreatefundedpsbt RPCBitcoin Core
Funding inputs, watch-only inclusion, fee rate and change outputs.
Locator: Arguments: inputs, outputs, options; Result · Version / scope: Bitcoin Core 29.0 RPC reference; not a recommendation to install an old release · Retrieved: 2026-10-02T18:53:55.093ZOpen source - sendtoaddress RPCBitcoin Core
Fee subtraction changes recipient output; comments remain local metadata.
Locator: Description; Arguments: amount, comment, comment_to, subtractfeefromamount, fee_rate; Result · Version / scope: Bitcoin Core 29.0 RPC reference; not a recommendation to install an old release · Retrieved: 2026-10-02T18:53:55.005ZOpen source
Research and drafting use AI assistance. A separate automated review checks claims against primary sources; no external expert or named human review is implied. Publication, substantive editing, source retrieval and verification are recorded separately. This version was independently checked by an automated reviewer on 2 October 2026.
Editorial method and correctionsDegrees of Satoshi editorial project. “Sending all your bitcoin: why Send Max differs from the displayed balance.” Published 2026-10-02; updated 2026-10-02. https://degreesofsatoshi.com/encyclopedia/bitcoin-send-max/