1. How Fee Replacement Works
All blockchain networks — Ethereum, Bitcoin, and others — prioritize transactions with higher fees.
If a transaction is sent with too low a fee, miners or validators may not pick it up, causing it to remain pending for a long time.
To resolve this, Bron enables fee replacement:
A pending transaction can be resent.
The new version uses a higher fee tier.
The network accepts the new transaction and discards the original.
This ensures your transaction is confirmed faster, without waiting for the old one to expire.
2. Why Transactions Get Stuck
ANY fee tier (Slow/Average/Fast) can become too low if network conditions change.
When you choose Slow, Average, or Fast, you are selecting a fee that is appropriate at that moment based on current network conditions.
However, blockchain fees fluctuate rapidly. Even if you choose Average or Fast, your transaction may still remain unconfirmed if network congestion suddenly increases or if miners begin prioritizing only higher-fee transactions.
When network conditions change after you submit a transaction:
Miners may ignore your transaction.
Validators may skip it in upcoming blocks.
The transaction can remain pending indefinitely until the network fee rises again.
In these cases, replacing the pending transaction with a new version—using an updated Average or Fast fee—ensures the fee is competitive and increases the likelihood that miners will confirm it promptly.
3. Fee Tiers in Bron
When sending any asset (ETH, BTC, USDT, tokens, etc.), Bron provides real-time fee estimates:
Slow
Lowest cost
Longest confirmation time
May be ignored by the network during congestion
Average
Balanced speed and price
Suitable for most transfers
Fast
Highest priority
Preferable during network spikes
Bron calculates these values dynamically based on current network conditions.
4. Speeding Up a Pending Transaction
If a transaction remains unconfirmed, you can increase its fee:
Open the pending transaction in your Activity tab.
Tap Recreate.
Select a higher fee tier (Average or Fast).
Bron will broadcast the updated transaction.
The new version will use:
A higher fee
The same nonce (Ethereum and EVM networks)
A replacement flag or higher sat/vB (Bitcoin and BTC-derived networks)
Once confirmed, the original transaction is safely discarded by the network.
5. Supported Networks
Bron supports fee replacement on all major chains, each using its native mechanism:
Ethereum & EVM Networks (ETH, Polygon, Optimism, etc.)
Uses nonce replacement
A new transaction with the same nonce and higher fee overrides the old one
6. When You Should Replace a Transaction
You should speed up a transaction if:
It has been pending longer than expected
Network conditions have changed and your original fee is no longer competitive
You selected Slow, Average, or even Fast, but fees increased after you submitted the transaction
You need a time-sensitive confirmation
Validators or miners are not including your transaction because its fee is now too low
Fee conditions on blockchain networks can change rapidly. A transaction that was appropriately priced a few minutes ago may become “slow” later if network congestion increases.
Increasing the fee ensures your transaction remains competitive and is prioritized for confirmation.
7. Transaction Safety
Replacing a transaction does not duplicate or double-spend funds. Only one version will confirm.
The network accepts the highest-fee version.
The abandoned version becomes invalid automatically.
Funds remain safe throughout the process.
Bron ensures each replacement follows the network’s rules.
If you have questions, contact our support team via messenger on the Bron platform or by email support@bron.org.