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Sending a payment

From signing to confirmation, and why there is no undo.

4 minChecked 4 October 20268 sources

Animation is off, so this lesson is a plain page: one still picture and a few sentences for each step. Turn animation on in the menu to watch it play.

Your walletSigns with your key
Your payment · signed
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Step 1 of 5

You sign the payment

Your wallet builds the payment and signs it with your key. The signature proves you approved it without revealing the key.

  1. Your walletSigns with your key
    Your payment · signed

    Step 1 of 5

    You sign the payment

    Your wallet builds the payment and signs it with your key. The signature proves you approved it without revealing the key.

  2. Your walletSigns with your key
    Pending payments (the mempool)
    Payment · fee 5
    Payment · fee 2
    Payment · fee 1
    Your payment · signed

    Step 2 of 5

    It waits in a queue

    The signed payment is sent to the network and waits with other pending payments in a pool, often called the mempool. Payments offering higher fees are usually picked first. Try it below.

    Try it

    Your fee

    Payments offering more are usually picked first, so yours may wait.

  3. Your walletSigns with your key
    Pending payments (the mempool)
    Payment · fee 2
    Payment · fee 1
    Your payment · signed
    1 confirmationYour payment is in a block

    Step 3 of 5

    A block includes it

    A new block includes the payment. That is its first confirmation, and every block added after it is one more. For large Bitcoin payments, the usual guidance is to wait for six.

  4. Your walletSigns with your key
    Pending payments (the mempool)
    Payment · fee 2
    Payment · fee 1
    2 confirmationsOne more block on top
    Average Ethereum fee: about $0.074 Oct 2026 · about $0.002 on layer 2

    Step 4 of 5

    Fees go up and down

    Fees depend on demand. On 4 October 2026 an average Ethereum transaction cost about $0.07, and on layer 2 networks, which batch transactions, about $0.002.

  5. Your walletSigns with your key
    Pending payments (the mempool)
    Payment · fee 2
    Payment · fee 1
    No undoConfirmed payments are final
    Check the whole addressLook-alikes are planted by scammers

    Step 5 of 5

    What can go wrong

    A confirmed payment cannot be reversed. Coins sent to a wrong address are usually gone for good. Check the whole address, and watch for look-alike addresses that scammers plant in your history.

Quick check

Did it stick?

2 questions. Get them right to complete the lesson.

Question 1

Question 1 of 2

What can you do once a payment is confirmed?

Question 2

Question 2 of 2

Which payments are usually picked first?

Or skip ahead to lesson 4: Bitcoin.

Sources

Checked 4 October 2026
  1. Bitcoin developer guide: transactionsBitcoin Project
    • The signature proves you approved it without revealing the key.
    • Fees depend on demand for space in blocks.
  2. Ethereum transactionsethereum.org
    • Your wallet builds the payment and signs it with your key.
    • The signed payment is sent to the network and waits with other pending payments in a pool, often called the mempool.
  3. Gas and feesethereum.org
    • Payments offering higher fees are usually picked first.
  4. Some things you need to knowbitcoin.org
    • A block that includes the payment is its first confirmation, and every block added after it is one more.
    • For large Bitcoin payments, the usual guidance is to wait for six confirmations.
    • A confirmed payment cannot be reversed.
    • Coins sent to a wrong address are usually gone for good: only the receiver can send them back.
  5. Layer 2ethereum.org
    • On 4 October 2026 an average Ethereum transaction cost about $0.07, and on layer 2 networks about $0.002.
  6. Optimistic rollupsethereum.org
    • Layer 2 networks batch transactions and post them to Ethereum.
  7. Address poisoning scamsChainalysis
    • Scammers plant look-alike addresses in your history.
  8. BIP-141: Segregated Witness (block weight limit)Bitcoin Improvement Proposals
    • Space in each block is limited.

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