ACH Forms

R04 ACH return code: Invalid Account Number Structure

What R04 means

The account number is not in a valid format for that bank. It has the wrong number of digits or fails the bank's own check.

Checked against 7 sources. Last reviewed .

R04 key facts

Official title Invalid Account Number Structure
Other names you may see Invalid Account Number. A shorter form of the title. A Federal Reserve manual and an EPCOR guide use it.
Returned by Receiving bank (RDFI)
Time frame 2 banking days
The receiving bank must send the return so that it reaches the sending bank by the opening of business on the second banking day after the payment settled.
Applies to Consumer and business accounts
Can you send it again? Yes, once you have the correct account number. A new payment to the correct account is not treated as a reinitiated entry.
Type of return Standard return. Counts toward the administrative return rate (3% level).

Why R04 happens

  • A digit is missing or an extra digit was typed.
  • Spaces, dashes or letters were included in the account number.
  • The routing number or a card number was entered in the account number field.

What to do next

If you collected the payment from a customer

  1. Ask the customer for the account number again and compare it with a check or bank letter.
  2. Correct your records and send a new payment. A new payment to the correct account is not counted as a retry.

Message you can send the customer

Change the words in [square brackets] before you send it.

Hello [name], Your ACH payment of [amount] dated [date] was returned because the account number we have is not valid (return code R04). Please check your account number and send us the correct details on a new form, so we can update our records. Thank you, [business]

Need a form to send with it? Make an ACH authorization form.

If you paid someone (payroll or a supplier)

  1. The payment goes back to the bank that sent it (the originating bank), and from there to the sender. If a payroll service sent it for you, ask the service about it.
  2. Ask the employee or supplier for their account number again, on a direct deposit form (an employee) or a vendor ACH form (a supplier).
  3. Confirm the new details with the person in person, or by calling a phone number you already had (not one from the email or the form). See ACH fraud prevention.
  4. Update your records and send a new payment to the correct account.

Message you can send the employee or supplier

Change the words in [square brackets] before you send it.

Hello [name], We tried to pay you [amount] on [date], but the payment came back because the account number we have is not valid (return code R04). Please check your account number and send us the correct details on the attached form, so we can pay you again. Thank you, [business]

Need a form to send with it? Make a direct deposit form for an employee or a vendor ACH form for a supplier.

If you got the notice about your own account

  1. Look up your account number in your bank app or on a check, and send it again.

Got a return file from your bank? Open it in the ACH file viewer to see the code next to each payment.

Questions and answers

Is R04 the same as "invalid account number"?

Yes. Some banks and software shorten the title to "Invalid Account Number". The full Nacha title is Invalid Account Number Structure.

Sources

  1. ACH Network Risk and Enforcement Topics (return rates, reinitiation), Nacha
  2. ACH Risk Management 2023: Proposed Modifications to the Rules (Table of Return Reason Codes excerpt), Nacha
  3. Green Book: A Guide to Federal Government ACH Payments, US Treasury, Bureau of the Fiscal Service
  4. 2024 ACH Quick Reference Guide, EPCOR
  5. 2024 ACH Quick Reference Guide for Corporate Users, EPCOR
  6. FedGlobal ACH Payments Origination Manual, Federal Reserve Financial Services
  7. Cyber Criminals Conduct Business Email Compromise through Exploitation of Cloud-Based Email Services (verify payment changes in person or on a known phone number), FBI Internet Crime Complaint Center

Last reviewed . How we check our information. Report a mistake on this page.

General information, not legal or financial advice. Rules change and banks set their own requirements. Check with your bank before you act. ACH Forms is not affiliated with Nacha.