Queued Transaction Meaning
What Is a Queued Transaction?
When a user initiates a blockchain transaction, it is not directly approved. Once the user has signed the transaction, they rely on miners or validators to process and include it in the next block. Typically, the transaction first goes to each node’s mempool, a sort of waiting room that stores and sorts unconfirmed transactions. Within the mempool, the unconfirmed transactions fall into two states: pending and queued.
Queued transactions are the transactions that are yet to be validated. That is, the transactions are not available for processing and cannot be added to the next block. The queued state may occur for two main reasons:
- Older transactions are still pending and must be processed first.
- The transaction has an incorrect nonce, i.e., the transaction nonce (not block nonce) does not follow the nonce ordering. Nonce is the number that increments by 1 with every transaction executed on your account.
In simpler terms, if the submitted transaction contains a higher count than the existing transaction count, the transaction goes to a queued state. It remains queued until the existing gap is filled by submitting another transaction with the correct nonce and subsequently processing it.
Queued vs pending transactions
Pending transactions are transactions that miners or validators have already validated and can be included in the next block. On the other hand, transactions in a queued state are yet to be validated. They become pending transactions once the nodes check the validity of the user’s signature and verify that the account holds the necessary digital assets to facilitate the transaction. The miners and validators can then add the validated transactions to the next block.
You can check the status of your transaction using blockchain explorers such as Etherscan, Ethplorer, or EthVM for Ethereum transactions and BTCScan or Bitcoin Explorer for Bitcoin transactions. It is as simple as typing the transaction ID/hash or public address and hitting the “search” button to check whether the transaction is queued, pending, or confirmed.