I sent a transaction from the blockchain.info wallet, but accidentally indicated too small commission. How can I cancel this transaction or speed up its confirmation?
There are several options for action, but none of them is 100% reliable. I’m not sure which methods are most applicable to blockchain.info, but it could probably be # 0 and # 2, followed by # 3 and # 1b.
0) Just wait. Even at the end of 2017, there are times of a minimum load on the network from time to time when transactions are conducted even with the most minimal commission. This usually happens on Sunday evening. After about 2 weeks, the transaction will eventually be processed by the network, although it can be retransmitted, with both the sender and the recipient or a third party.
0b) Retransmission: most likely it will not help, but while you are still waiting for the transaction, you can try to transfer it again (not sure how much it is possible to make from the blockchain.info wallet, but you can use third-party software).
1a) Commission substitution (repair by Fee, RBF): In 2017, many miners allow double spending only when it is done using the RBF protocol. In order to be able to use RBF, the original transaction must have the status of “replaceable” – only a few wallets have support for this function. In blockchain.info, this option is probably absent, so this method is most likely not suitable for you. Nevertheless, I mention it, as this is probably the best way to speed up a stuck transaction. RBF can be used – theoretically, since most wallets do not have such an option – also to cancel an existing transaction, but only until it has received a single confirmation. Making all outgoing transactions replaceable by default may not be the best idea – if you pay for such a transaction with, say, coffee, then there is a high probability of getting it already completely cooled.
1b) Double waste with a higher commission: this is usually only possible if the initial transaction is marked RBF, but just in case it may be worth a try – it will suddenly get lucky. You may have to use another wallet or even specialized programs for this. This may work or if the transaction has become “phantom” (when only some nodes are aware of it, but not others) – maybe some miners will not notice that you are doing double waste – or it may work, due to the fact that some miners deliberately accept transactions with double waste, as they can get more reward for them.
2) A child pays for a parent (Child Pays for Parent, CPFP): if a new transaction created over the previous one contains a high commission, then most miners will inсlude the entire transaction chain in the unit being formed.
2a) The recipient of funds spends the amount received through a new transaction, with a higher commission. Of course, this is not always possible, but still…
2b) If the transaction has not completely emptied the wallet, then the UTXO change option (Unspent Transaction Output) should be available in your wallet. If you manage to use it with a higher commission, then the transaction is likely to go faster. Some wallets provide the ability to make a CPFP transaction. If CPFP transactions are not explicitly supported, you can always try a new transaction to withdraw all funds from the wallet (then you can send them back to the same wallet). Be careful if you have been using the wallet for some time and have never completely emptied it – the amount of the commission can be uncontrollable, since many tiny balances from previous payments have accumulated in the wallet. The transaction can be edited so that it only includes a change in UTXO. I am not very familiar with blockchain.info. In the worst case, you can move the secret key or wallet recovery key to another wallet. For example, Electrum has support for changing certain UTXOs.
3) Ask pools for help. ViaBTC has a “transaction accelerator” feature at this address: https://pool.viabtc.com/tools/txaccelerator/, antpool.com also has this feature. There are even services that allow you to pay to increase the priority of a transaction with a credit card.
Source: chby.io
