USDC Sent but No API Credit? A Checklist for Stuck Deposits on Base

Introduction

You sent USDC on Base to top up your API credit, but the balance hasn't updated. This can be frustrating, but most cases are straightforward to diagnose. This checklist will help you confirm what happened and what to do next.

Step 1: Confirm the Transaction on a Base Explorer

First, verify that your transaction was actually mined and confirmed on the Base network.

• Locate your transaction hash (tx hash) from your wallet's activity history.
• Open a Base block explorer (e.g., Basescan) and paste the tx hash into the search bar.
• Check the status: it should say "Success" and show a confirmed block.
• If the status is "Pending" or "Failed," the funds did not reach the destination. You may need to retry the transfer.

Step 2: Check for Bridged vs Native USDC

Base supports both native USDC (issued by Circle) and bridged USDC (USDC.e, bridged from Ethereum). While both are USDC, they are different tokens with different contract addresses.

• If you sent USDC.e (bridged) instead of native USDC, the deposit may not be automatically credited.
• Check the token contract address of the asset you sent. Native USDC on Base has a specific contract address; USDC.e has a different one.
• If you're unsure, look up the token symbol in your wallet or on the explorer. If it shows "USDC.e" or "Bridged USDC," that's likely the issue.

Step 3: Verify the Destination Address

A simple typo or copy-paste error can send funds to the wrong place.

• Double-check the recipient address you used. It should match the deposit address provided by your API aggregator.
• Ensure you sent to the correct network (Base). Sending USDC on another network (e.g., Ethereum, Polygon) to a Base address will not credit your account and may result in lost funds.
• If you used a smart contract wallet or exchange withdrawal, confirm that the withdrawal was sent to the correct address and network.

Step 4: Check for a Missing Memo or Tag

Some services require a memo or tag to identify your deposit. While many API aggregators using USDC on Base do not require a memo (since the address is unique to you), it's worth checking.

• Review the deposit instructions to see if a memo/tag was required.
• If you omitted it, the funds may still be recoverable, but you'll need to contact support.

Step 5: Allow for Processing Time

Blockchain transactions are usually fast, but credit may not be instant.

• Some services wait for a certain number of confirmations before crediting.
• There may be manual review for large deposits or first-time senders.
• Wait a reasonable amount of time (e.g., 30–60 minutes) before assuming something is wrong.

Step 6: Gather Information for Support

If you've gone through the steps above and still don't see your credit, contact support. To speed things up, include:

• Your transaction hash.
• The amount and token (USDC or USDC.e).
• The destination address you sent to.
• The date and time of the transaction.
• Any screenshots or relevant details.

Support can then trace the transaction and help resolve the issue.

Conclusion

Most USDC deposit issues on Base are due to simple mistakes like wrong token type, wrong network, or missing memo. By following this checklist, you can quickly identify the problem and provide support with the information they need to help you.