A pending swap transaction has been broadcast but has not yet been included in an Avalanche C-Chain block; a failed one was included and its contract call reverted. The key is to check the transaction hash on a block explorer first, because a wallet’s pending label can be stale and the right next step depends on the on-chain status.
If you’re trying to exchange tokens or find liquidity on Avalanche, Blackhole swap is a decentralized exchange on the C-Chain. The same recovery logic applies to a swap submitted there: first identify whether it is pending, confirmed, or reverted, then decide whether to wait, replace it, or submit a corrected transaction.
Check what happened on the C-Chain
Look up the transaction hash in an Avalanche C-Chain block explorer and compare its status with your wallet’s activity. A confirmed transaction usually reaches finality quickly after inclusion, according to the Avalanche Builder Hub, so a long-lived “pending” label is a reason to verify the hash rather than keep resubmitting the swap.
- Pending: the transaction has not been included in a block.
- Success: the swap call completed; check the token balance changes and receipt.
- Reverted: the transaction was included, but the swap call failed. The nonce is consumed and the network fee is still charged.
A reverted transaction cannot be repaired after the fact. Read the explorer’s revert reason or wallet error, then correct the underlying issue before trying again. Common causes include insufficient AVAX for gas, an expired quote, or a swap condition such as slippage protection rejecting the execution price.
Resolve pending transactions in nonce order
A nonce is the account’s sequential transaction number. A pending transaction can block later transactions from the same address, so handle the oldest unresolved nonce first; MetaMask’s transaction guidance describes the same queue behavior for EVM-compatible networks.
- Find the oldest pending nonce. Compare pending transactions from your wallet address in the explorer or wallet activity. If several are stuck, start with the lowest nonce, since later transactions may be queued behind it.
- Decide whether to wait or replace. If the transaction is recent and the network is processing normally, waiting avoids paying a higher fee. If it has remained pending and you need to move on, use your wallet’s speed-up option or send a replacement with the same nonce and a higher fee.
- Check the fee before signing a replacement. The network fee is paid in AVAX, and a replacement may need a higher fee to be accepted. Fee markets change with network demand, so use the wallet’s current estimate; a fixed Gwei figure can quickly become misleading.
- Cancel only if you no longer want the swap. A cancellation is another transaction using the same nonce, often a transfer of zero AVAX back to your own address. It can win the race against the original only while both remain pending. If the swap has already confirmed, it cannot be cancelled.
- Retry a reverted swap only after checking its cause. For example, if an illustrative 20 USDT swap reverted because the quoted price moved beyond the selected slippage tolerance, review the quote and tolerance before submitting again. A larger tolerance can help execution, but it also permits a worse price.
Replacing a pending transaction does not mean both versions execute: only one transaction for a given nonce can be accepted. Once a replacement confirms, check its result in the explorer and refresh your wallet’s activity; if the explorer shows success but the wallet still looks stuck, the on-chain receipt is the reliable record.
Decision rule: wait on a recent pending transaction, replace the oldest one if it is blocking you, and correct the revert cause before submitting another swap.