Sending

To send bitcoin, you give your wallet a recipient address, an amount and a fee. The wallet signs the transaction and sends it to the network. Your payment is confirmed when a block includes it. A payment is very hard to undo once a block holds it, so check every detail before you send.

How do you send bitcoin?

Every wallet asks for the same three things:

• The address. This is where the coins should go.
• The amount. It is in bitcoin (BTC) or in satoshis (sats). One bitcoin is 100,000,000 sats.
• The fee. This is what you pay the miners, and it sets how quickly they pick up the payment.

Then you review the details and confirm. Always check the amount and the address, because a payment cannot be undone. If you send coins to the wrong address, they belong to whoever controls that address.

What is a bitcoin address?

An address is a short string that stands for a lock. When you send, your wallet puts that lock on the new coins, and only the owner of the matching key can unlock them later. Addresses start with 1 or 3, or with bc1q (SegWit) or bc1p (Taproot). The address page has the details.

An address has a checksum, a short code built from the rest of the address. The checksum catches most typing mistakes, so a mistyped address is rejected rather than used. It cannot tell you whether the address belongs to the right person, though. Malware on your device can swap an address you copied for one it controls, and the checksum still passes.

So compare the address on the screen with the one you meant to use. Check every character if you can, and at least the first and last few. For large sums, send a small test amount first.

What is a fee, and how much should you pay?

A fee is the difference between the coins that go into a transaction and the coins that come out of it. Miners keep the fee. They choose the transactions that pay the most for the space they take, because a block has room for only so much data.

Fees are measured in sats per virtual byte, written sat/vB. A virtual byte is a unit of transaction size. A block holds at most about 1 million virtual bytes, so when many people send at once, the transactions with the lowest fee rates wait longer.

Most wallets suggest fees for a target time. A higher fee moves your payment up the line, and a lower fee is fine if you can wait. Treat your wallet's estimate as a guide, not a promise. A payment with a fee rate far below the others can wait a long time. The fee rate page explains the unit in more detail.

What happens after you send?

Your wallet sends the transaction to a node. The node passes it along, and each node keeps it in its mempool, the waiting list for transactions that are not yet in a block. Then a miner builds a block from waiting transactions and finds a valid hash for it. The block is shared with the network, and each node adds it to the blockchain.

Until your payment is in a block, treat it as pending. A payment in the mempool can still be dropped. Many nodes drop a waiting transaction after a set time. The default in Bitcoin Core is 336 hours, or two weeks.

How many confirmations do you need?

A confirmation is a block that includes your transaction. The block that holds it counts as the first. Each block added on top counts as one more. New blocks arrive about every 10 minutes on average, so the first confirmation usually takes about that long if your fee is high enough.

• 1 confirmation is enough for most small payments.
• 2 or more is better for larger sums. Now and then two miners find blocks at almost the same moment, and the network keeps only one of them. A payment in the newest block can then move. Once another block sits on top, it is far less exposed to this.
• 6 or more is what many people wait for before a very large transfer.

The confirmation page goes into more detail. The chain reorganization page explains the rare case where the newest blocks change.

How do you track a payment?

When you send, your wallet gives you a transaction ID, or TXID. It is a reference number for that payment. Paste it into a block explorer, such as our explorer, to see whether the payment is still waiting or has been confirmed.

What if your payment is stuck?

A payment with a low fee can wait in the mempool for a long time. If the payment was sent with replace-by-fee, your wallet can often raise its fee. The person who received the payment can also spend those coins in a new transaction with a higher fee. This is called child pays for parent. The stuck transaction guide walks through both options.

Do not send the same payment again from scratch. If you send it with new coins, the first payment may still confirm, and then you have paid twice.

How do you receive bitcoin?

Give the sender an address from your wallet. Many wallets create a new address for each payment, so use a new address each time when your wallet offers one. Reusing a single address makes it easier for others to see all the payments that reach you.

What next?

Security explains how to protect the keys behind your wallet and your coins, and what to do before you move a large amount.