Issue

If a transaction status is Confirming or Broadcasting for a long time, it likely means that you have not entered a high enough fee.

Ethereum and EVM-based blockchain transaction fees vary depending on network activity. Spikes in transaction fees (gas price) can cause transactions with low transaction fees to get stuck in the mempool with 0 confirmations. These are transactions that have yet to be incorporated by miners into the blockchain.

Miners incorporate transactions based on the fee or gas price paid with the transaction. Transactions with higher fees are prioritized over transactions with lower fees. Ethereum and EVM-based networks require transactions originating from the same account to be confirmed in sequential order. Therefore, a stuck transaction will prevent later transactions from being processed.

Resolution

These blockchains support replacing a transaction that is pending in the mempool with a higher fee transaction in order to confirm the initial transaction more quickly. The replacement transaction fee must meet specific requirements to be incorporated into the blockchain.

Replace-by-Fee (RBF) is a mechanism that allows users to boost or drop a transaction or contract call on Ethereum and other EVM-based networks.

Learn more about boosting a stuck UTXO transaction using the API.

Boost transaction

Boost transaction uses RBF to raise the priority of the original transaction.

1. Open the Recent activity panel.
2. Identify the stuck transaction, then select (Boost). The Replace by Fee dialog opens with the transaction's details already entered and the fast fee pre-selected.
   
3. Confirm or enter a new fee to replace the previous fee. Note that the new fee must be at least 15% greater than the original fee.
4. Select Create Transfer.
5. The new transaction requires approval and signing according to your workspace settings.
   

Drop transaction

Drop transaction uses RBF to replace the original transaction with a new transaction of 0 value, and a destination identical to the source, effectively canceling the transfer. A transaction can only be dropped if the asset currently has a valid US Dollar ($USD) value. Learn more about USD conversion rates.

1. Open the Recent activity panel.
2. Identify the stuck transaction, then select (Drop). 
   
3. Confirm the higher fee and select Drop Transaction.
   
4. The new transaction requires approval and signing according to your workspace settings.
   

All other queued transactions from the same source vault account will continue processing. Learn more about queued transactions.

After you drop the transaction, you can create a new transfer with a current gas price.

How does this work?

You can use the Replace by Fee (RBF) mechanism to boost and drop transactions due to a sequence nonce that is associated with every Ethereum account. The sequence nonce for an Ethereum account represents the number of transactions that Ethereum account has initiated. 

When you use RBF to boost or drop a stuck transaction, the Fireblocks algorithm replaces the stuck transaction by submitting another transaction with the same nonce as the original transaction. Whether you will boost or drop a stuck transaction, the nonce is needed to use either RBF method:

• Boost: Replaces a failed transaction by initiating another similar transaction with the same nonce, destination, and amount, but with a higher fee. After the new transaction is selected and mined, the original transaction becomes obsolete.
• Drop: Replace the original transaction with a new ETH transaction with “0” as the amount. It has the same nonce as the original transaction and makes the original transaction no longer valid.

An EVM-based transaction completed on the blockchain, but is stuck or not displayed as complete in your Fireblocks Console

Check how many confirmations the transaction has on a blockchain explorer and compare it with your confirmation policy.

If you can not resolve this issue, contact Fireblocks Support.