This ACH return code indicates that the company identification number entered in your ACH transaction is invalid, incorrect, or doesn't match the receiving bank's records. R21 is commonly used for Customer Initiated Entry (CIE) transactions where proper company identification is required for processing. This is typically a data entry error rather than an account issue.
Error message: "The identification number used in the Company Identification Field is not valid. This Return Reason Code will normally be used on CIE transactions."
What Causes ACH Return Code R21?
The R21 ACH return code means "Invalid Company Identification" and indicates that the company ID number provided in your ACH transaction doesn't match the receiving bank's records or is formatted incorrectly. This most commonly occurs with Customer Initiated Entry (CIE) transactions where businesses need to provide valid company identification for the receiving bank to process the payment.
Company identification numbers are used by receiving banks to validate the legitimacy of business transactions and ensure proper routing of funds. When the provided company ID is missing, contains typos, is outdated, or simply doesn't exist in the bank's database, the transaction will be returned with an R21 code. This serves as a security measure to prevent unauthorized or fraudulent business transactions.
Can You Retry R21 Payments?
You can retry R21 payments after verifying and correcting the company identification information. Contact the customer to confirm their correct company ID number, check for any typos in your records, and ensure you're using the most current identification information before resubmitting the transaction.
How to Respond to an R21 Code
An R21 return requires verifying and correcting the company identification information used in the transaction before reprocessing the payment.
When Your Customer's Payment Fails
- Double-Check Company ID Information
Review the company identification number in your records for any typos or formatting errors. - Contact Customer for Verification
Reach out to confirm their correct company ID number and check if it has been updated recently. - Verify Current Registration Status
Ensure the company ID is still active and hasn't expired or been revoked. - Correct and Resubmit
Update your records with the verified company identification information and reprocess the transaction.
Subject: Payment Processing Issue - Company ID Verification Needed
Hi [Customer Name],
We encountered an issue processing your recent payment due to an invalid company identification number in our records. This could be due to a typo or outdated information.
To complete your payment, could you please verify your correct company identification number? We want to ensure we have the most current information to process your transaction successfully.
Once we receive the correct company ID, we'll update our records and reprocess your payment immediately.
Thanks,
[Your Company Name]
When Your Payment to Vendors Fails
An R21 return on vendor payments means the company identification information you have for the vendor is invalid. You'll need to contact them to verify and update their company ID before reprocessing.
- Contact the vendor to verify their current company identification number
- Check your records for any data entry errors or typos in the company ID
- Confirm the company ID format meets the receiving bank's requirements
- Update your vendor records and resubmit the payment with the correct company identification
Get Unlimited Free ACH Payments
Get unlimited free ACH transfers, smart retries, and real-time payment visibility with Nickel.
Free unlimited ACH transfers
Smart retry scheduling
Real-time payment visibility

Don't just take our word for it
See why thousands of small business owners trust Nickel.