Troubleshoot CCTP transfers

Diagnose and resolve stuck or failed crosschain USDC transfers

This guide helps you diagnose and resolve issues with CCTP transfers that appear stuck or fail to complete. A CCTP transfer involves three stages, and problems can occur at any point in the process.

Transfer stages

A CCTP transfer consists of three stages:

1. Burn: USDC is burned on the source blockchain
2. Attestation: Circle’s Attestation Service observes the burn and signs a message
3. Mint: The signed attestation is submitted to mint USDC on the destination blockchain

If your transfer appears stuck, first identify which stage has the issue.

Identify where your transfer is stuck

Use the following steps to determine the current state of your transfer:

1. Check the burn transaction

   Verify the burn transaction succeeded on the source blockchain using a block explorer. If the transaction failed or is pending, the issue is at the burn stage.

2. Query the attestation API

   Call the GET /v2/messages endpoint with your transaction hash.

   Interpret the response:

   • 404 response: The attestation service hasn’t observed the burn yet. This is normal and expected. See Why 404 responses are expected.
   • Empty messages array: The burn exists but hasn’t been processed yet.
   • Status pending: The burn is awaiting block confirmations.
   • Status complete with attestation: The attestation is ready. If your transfer is stuck, the issue is at the mint stage.
3. Check the mint transaction

   If you have an attestation but your destination wallet doesn’t have the USDC, either:

   • The mint transaction was never submitted
   • The mint transaction failed

   Check your destination blockchain for any failed receiveMessage transactions.

Common issues and solutions

Issue	Cause	Solution
404 persists for extended time	Burn transaction may have failed or is still confirming	Verify burn succeeded on block explorer. If it failed, retry the burn.
Attestation status remains pending	Waiting for block confirmations	Wait for sufficient confirmations based on finality threshold
Have attestation but mint fails	Gas issues, incorrect parameters, or nonce already used	See Retry a failed mint
expirationBlock has passed before you submitted the mint	Attestations encode an expirationBlock 24 hours in the future. Once that block passes on the destination blockchain, the existing attestation can no longer be used to mint.	Call POST /v2/reattest/{nonce} to request a new attestation with a refreshed expirationBlock, then poll GET /v2/messages and re-mint.

Expired messages are not permanently stuck

There is no deadline after which re-attestation becomes unavailable. As long as the original burn transaction still exists on the source blockchain, you can request a fresh attestation at any time using the re-attest endpoint.