120 votes

Why is my transaction not getting confirmed and what can I do about it?

How Bitcoin Mining Works Bitcoin transactions are mined (processed) by Miners, and Miners want to benefit from their work. By mining transactions with higher fees, they make more money. Some miners ...
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  • 1,453
25 votes

Why is my transaction not getting confirmed and what can I do about it?

In the case that your fee is too low: Now that child-pays-for-parent has been merged, you(or any of the recipients of your unconfirmed transaction) could spend the Bitcoin received and the fee ...
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  • 1,034
24 votes

Why is my transaction not getting confirmed and what can I do about it?

Here is a guide for as many wallets as I could figure out how to perform an RBF with. This is adapted from my bitcointalk post: https://bitcointalk.org/index.php?topic=1802212.0 What is a "Stuck" ...
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13 votes
Accepted

What is the Lightning Network proposal? What problem is it trying to solve?

Two issues with Bitcoin's design Scalability of "everyone checks everything" Bitcoin is a gossip network: P2P nodes connect mostly randomly to each other and pass-on new information to each ...
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  • 64.5k
13 votes

Why is my transaction not getting confirmed and what can I do about it?

The other answers cover most useful information already, I'd like to add one point though: The fee estimation of most wallets has significantly improved since blocks have gotten full. If you're ...
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10 votes
Accepted

If Bitcoin transactions require ~10 min to clear, how can payments get recognized within seconds?

When you create a transaction, your Bitcoin wallet broadcasts it to a few full nodes on the Bitcoin peer-to-peer network. Those full nodes quickly relay it to other full nodes, and it eventually ends ...
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8 votes

Why is my transaction not getting confirmed and what can I do about it?

If you are using Electrum, there is no equivalent to -zapwallettxes. The closest thing you can do is to restore your wallet from a seed. This will wipe your client of any unconfirmed transactions. ...
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  • 28.8k
6 votes
Accepted

What does a merchant need to do to reject RBF transactions

Replace-by-fee (RBF) transactions all have a sequence number that is below MAX - 1. If the payment a merchant receives comes from a transaction that has such a sequence number, the merchant can ...
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  • 8,734
5 votes
Accepted

Could any standard fee transaction be double spent by using a higher fee?

The original design assumes a common behavior of processing the incoming transaction on FIFO basis. That means the first transaction received by a miner wins and all conflicting transactions received ...
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  • 1,394
4 votes

How secure is zero confirmations?

It has become trivial to double-spend; do not accept zero-confirmation transactions!* Accepting zero-confirmation transactions today is not safe: Especially, with the full blocks of late, it is ...
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  • 64.5k
4 votes

Why is this unconfirmed?

This transaction (e8c5...) will never confirm because its inputs have already been spent by transaction 93cc4fe50e6069dccb827f56636bb4cd20f9865dd4d7e3b7946bbbca97576e80, which currently has 9 ...
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4 votes

It's possible to spend a BTC without fee to forge a payment?

The simplest protection is to not consider a payment to have been made to you until it receives some number of confirmations. The number can depend on the value of the payment. For small payments, one ...
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4 votes
Accepted

What restrictions are there to the application of opt-in RBF?

What restrictions are placed on RBF in the deployed "opt-in RBF" variant? BIP-125: Opt-in Full Replace-by-Fee (RBF) Signaling specifies how to declare transactions replaceable until they are ...
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  • 64.5k
4 votes

Could decentralised proof of time in BCHSV solve for high PoW power consumption?

Mining is the timestamp in Bitcoin, it allows for a decentralized system to achieve synchronized ordering of transactions with high probability. If a system for doing decentralized time sync existed ...
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  • 15.1k
3 votes

If Bitcoin transactions require ~10 min to clear, how can payments get recognized within seconds?

I think David ilustrated very well how things works, but I feel your question was not fully answered since you asked about time. So I will try to complete the answer above. As David said in the ...
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3 votes

Could Bitcoins (or any other blockchain based cryptocurrency) feasibly ever be used for purchases that need to go through fast?

Blockchain technology, at least without accepting central party that controls access to the chain, inherently has slow blocks, or strong centralization incentives. The reason is that blocks need to ...
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3 votes

Why is my transaction not getting confirmed and what can I do about it?

There's many ways to get your transaction confirmed. push your transaction https://insight.bitpay.com/tx/send https://blockchain.info/pushtx https://blockexplorer.com/tx/send ...
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  • 3,569
3 votes

Why is my transaction not getting confirmed and what can I do about it?

Note: In the 2017 fee event, accelerators were widely used, but they seem to be rather expensive today in 2020. YMMV. There are some services that take out-of-band requests to prioritize transactions ...
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  • 1,825
2 votes
Accepted

Why were BTC not accepted in the Humble Borderlands Bundle?

Fraud. Estrella (Humble Bundle) Jun 23, 15:46 Hi there, Thanks for writing in to Humble Bundle Support! Unfortunately, Bitcoin has been disabled for the Humble Borderlands Bundle. ...
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  • 28.8k
2 votes

If Bitcoin transactions require ~10 min to clear, how can payments get recognized within seconds?

Let us firstly divide the stages of the transaction into 2 major categories for better understanding. Stage 1: Initiation of the transaction (Mempool) In this stage, ALICE (sender) broadcasts a ...
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2 votes
Accepted

Is there a way for merchants to insist on a tx fee to increase likelihood of the tx (eventually) being accepted into the blockchain?

In short, no. You can tell the customer whatever you want on your webpage, at your point of sale, or in the memo field of a BIP70 invoice---but once the transaction has been sent to the network, ...
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2 votes

Why is my transaction not getting confirmed and what can I do about it?

If I had seen Andrew's great reply earlier, I would probably spared myself from writing an explainer on Reddit, but now that I did I'll post it here as well, hoping that it might complement this ...
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2 votes

What is the risk of waiting for just one confirmation to validate a transaction, assuming the counterparty is not a miner?

Should I be worried of such blockchain reorganizations when accepting n-confirmation transactions? Forks do occur quite frequently, and if you're only requiring a single confirmation the ...
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2 votes
Accepted

0/confirmation race attack double spend transactions

The bottom line is that there is no way for you to safely accept zero confirmation transactions. What happens if a miner (which has transaction A in his main memory) gets the conflicting ...
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  • 15.1k
2 votes

It's possible to spend a BTC without fee to forge a payment?

Yes, it is possible to make such a transaction. It's possible to make all kinds of transactions. Of course, it's much more interesting whether such a transaction would be valid. And it would. A ...
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  • 3,154
2 votes

Can bitcoin be used for instant payment?

There are situations where accepting a 0-confirmation transaction is low risk, but that's certainly not generally advisable. Double spending a 0-conf transaction is very easy to do with high success ...
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  • 6,218
2 votes
Accepted

As a solo miner how can I prioritize my own unconfirmed transactions?

If you are the pool itself, or are solo mining you can use the prioritisetransaction command to add weight to your own transaction, if you are a client of a pool you do not have any control over what ...
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  • 15.1k
2 votes

As a solo miner how can I prioritize my own unconfirmed transactions?

With 150GH/s, at the time of writing, you would find one block every 1500 years. That means if you were solo mining, you'd be able to control the contents of a block once every 1500 years. Or in ...
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2 votes

Wasn't 0-conf more secure than Visa, before blocks got full and RBF was added?

No. A zero-confirmation transaction is not useful for anything. Satoshi used PoW specifically, because he was trying to answer how to trust a transaction(double-spending problem). Secondly, ...
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  • 588
2 votes
Accepted

ways to improve bitcoin tx finalization time

According to the Bitcoin wiki who refers to this Analysis of hashrate-based double-spending: No amount of confirmations will reduce the success rate to 0. If the attacker controls more hashrate than ...
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  • 2,712

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