Incoming transactions show up in your account almost instantly (within a few seconds) but will show as ‘Pending’ until there have been at least six network confirmations.
Once a transaction is verified, it will show Complete in green. This lets you know that the transaction cannot be reversed and that the funds can be withdrawn.
Coinbase runs its own digital currency nodes that communicate with the rest of the network. When you initiate a transaction, we broadcast it to the rest of the network so it can be confirmed.
Sometimes nodes may lose sync with the rest of the network for short periods of time. This can cause transactions to remain in the “Pending” state for longer than normal. Usually the delay is under an hour, and the transaction will eventually go through normally.
Occasionally, transactions are not accepted by the rest of the network and therefore are never considered to be ‘confirmed’.
Common causes of unconfirmed transactions
- Sending a very small amount with insufficient fees
All bitcoin transactions require a miner fee to be confirmed by the bitcoin network. When sending bitcoin you will be prompted to add a miner fee to make sure the transaction gets confirmed. If an insufficient fee is included, your transaction may never confirm.
- A double-spend of the same coins
Under normal conditions this should not occur with transactions generated by Coinbase (our backend systems are designed to prevent this), but in general if two transactions try to spend the same coins, one of them will never be confirmed by the network.
- Trying to spend unconfirmed coins
If you are trying to spend coins that appear as pending in your account, your transaction will not be generated until these coins confirm.
- The network is experiencing high volume
Sometimes there is a high volume of digital currency being sent globally, and there are more transactions than there is space available in each new block to include the transaction.