Incoming transactions show up in your account almost instantly but show as Pending until there have been enough network confirmations.
Once a transaction is confirmed, it will show Completed, indicating that the transaction can't be reversed and the funds can be withdrawn.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.
Our nodes may lose sync with the rest of the network for short periods of time, which can cause transactions to remain Pending longer than normal. Usually the delay is under an hour and the transaction will eventually go through normally.
Occasionally, transactions aren't accepted by the rest of the network and therefore are never considered to be confirmed.
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.
Double-spending the same coins
If two transactions try to spend the same coins, one of them will never be confirmed by the network. Normally, this shouldn't occur with transactions generated by Coinbase because our backend systems are designed to prevent it.
Spending unconfirmed coins
If you're trying to spend coins that are still Pending in your account, your transaction won't generate until the coins confirm.
High network volume
Sometimes there's 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.
Pending phone send transactions
If you've initiated a send to a recipient's phone number and the transaction is in a pending state, it means the recipient hasn't accepted it yet.
You can cancel the payment to return the funds to your account by following the steps below. This process can only be completed via the web (not the mobile app).
Go to Coinbase.com using a web browser on your desktop, laptop, tablet, or smartphone.
Log in to your account and select the asset of your pending transaction.
Locate and select the pending transaction to display the Cancel payment option.
Select Cancel payment.
Once the transaction is canceled, the funds will be available again in your balance.
If funds aren't accepted by the recipient within 30 days of the send, they'll be returned to your account.