Understanding R04 Return Codes for Plaid-Linked Bank Accounts

An ACH Return Code R04 indicates an "Invalid Account Number Structure," meaning the bank account number provided for a Transfer is incorrect, too long, too short, or invalid.

If you encounter a failed Transfer with an R04 return code specifically for a Plaid-linked bank accounts, this often times indicates that the tokenized account number from the OAuth connection at Plaid expiring or being revoked.

Background

Plaid uses Tokenized Account Numbers (TANs)—also known as Virtual Account Numbers (VANs)—provided by financial institutions to securely connect accounts without sharing real, full bank details. Primarily used by Chase, PNC, and U.S. Bank via OAuth, these unique, app-specific numbers enable secure ACH Transactions.

How to resolve R04 return codes

If this scenario is encounter, we recommend that you prompt the User to reconnect their account.

Plaid sends updates programmatically via webhooks. It's also recommended to create in app notifications when a User's account need to be reconnected. Please read Plaid's documentation for more information.

Additional troubleshooting

For more detailed information about tokenized account numbers and troubleshooting steps, check:

• The status of the Plaid token in your system

• Plaid's official documentation on tokenized account numbers:

  • Plaid | Virtual Account Numbers

  • Plaid | Updating Items via Link

  • Plaid | Introduction to Auth