A buyer paid me in bitcoin. When can I ship?
Check the payment reached your own address, then wait for at least one confirmation before you hand anything over. Before that, the buyer can still replace it.
1. Check that the payment reached your address
Ask the buyer for the payment’s transaction ID and look it up on UTXOHub, or open your own receiving address to see what has been paid to it. Find the output that pays your address, compare the whole address, and check its bitcoin amount against the price you agreed. If you agreed a price in dollars or pounds, agree which bitcoin amount that means before the buyer pays.
Check a Bitcoin payment, step by step2. Wait for at least one confirmation
A payment that is waiting to go into a block has zero confirmations, and it isn’t final. Until a miner puts it in a block, the buyer’s wallet can replace it with a new version that spends the same bitcoin and pays a higher fee. That new version can pay a different address, including one of the buyer’s own, and then your payment never arrives. Since Bitcoin Core 28.0, nodes accept a replacement by default even when the first version wasn’t marked as replaceable. Once the payment is in a block, it has its first confirmation and can no longer be replaced that way. The payment’s page on UTXOHub says how soon it is likely to confirm at its fee.
Why is my Bitcoin transaction unconfirmed?3. Wait longer for larger sums
Each block added after the payment’s block is another confirmation, and each one makes the payment harder to reverse. The Bitcoin developer guide notes that the newest block is sometimes replaced by accident, and says software handling high-value payments should wait for at least six confirmations. Blocks come about every ten minutes on average, so six take about an hour, sometimes much more. How many you wait for is your decision; no number suits every amount.
How many confirmations does a payment need?If the payment is stuck
A payment with a low fee can wait hours or days. The buyer can raise its fee from the wallet that sent it, and you can spend the bitcoin it pays you on with a higher fee, if your wallet lets you choose a waiting amount. Either way, it is still not confirmed until it is in a block. If the buyer offers to pay again instead, both payments could confirm, and only you could send the extra back.
How to speed up a stuck Bitcoin transactionShow the buyer where the payment stands
Send the buyer the payment’s UTXOHub link, which the Share button on its page copies or opens in your phone’s share menu. In most chat apps the link’s preview already says whether the payment is waiting or confirmed, and a waiting payment’s preview says to wait for a confirmation before handing anything over. While the page is open, it checks again every 30 seconds and updates by itself, so you both watch the same status rather than trading screenshots.
If one of you says it never arrived
Open the payment’s page and expand Bitcoin not received?. Mark the output that pays the seller’s address, and the page writes a summary with the status, the time, the transaction ID, the address and the amount, ready to copy. If the output matches but a wallet or exchange hasn’t shown it, that summary is what its support team asks for. If no output pays the seller’s address, the bitcoin went somewhere else, and only the buyer’s wallet history can say where.
Trust the network, not a screenshot or an email
A screenshot, a wallet saying Sent, or an email saying the payment went through doesn’t show that bitcoin reached you. Look the payment up yourself, or open your own address. Consumer Affairs Victoria warns that scammers posing as buyers send fake emails that look like they come from payment services, and may claim they paid too much and ask for the difference back. A Bitcoin payment can’t be reversed, only refunded by whoever received it, so check what has confirmed to your address before you send anything back. Nobody needs your recovery words to pay you.
How to check someone really sent you bitcoinWhat is a double spend?References
- Bitcoin Core, “Mempool Replacements”.
- Bitcoin Core, “Bitcoin Core 28.0 Release Notes”.
- Bitcoin Developer Guide, “Payment Processing”.
- Bitcoin Developer Guide, “Block Chain”.
- Consumer Affairs Victoria, “Online selling scam”.
- Bitcoin.org, “Some things you need to know”.