Account type: Consumer and Non-Consumer
Time Frame for Return: Next file delivery time after processing
SEC Codes: All
ISO Code: DT01
What is an ACH Return Code?
An ACH return code is a standardized code used to explain why an Automated Clearing House (ACH) transaction was returned by the receiving bank.
Codes are issued by the Receiving Depository Financial Institution (RDFI) and maintained by Nacha, the organization that governs the ACH Network. Certain codes may apply to consumer accounts, non-consumer (business) accounts, or both. These codes help banks, payment processors, and originators understand what went wrong during an ACH transaction so they can determine the appropriate next steps, such as retrying the payment, correcting information, or contacting the customer.
Why you're seeing ACH Return Code R18
Code R18 means the effective entry date on the ACH transaction was not valid. The effective entry date is the date the originator requests that the ACH entry settle and post to the receiver's account. This return may have occurred because:
- The entry date was too far in the future. ACH rules limit how far ahead an entry can be dated, and dates beyond that window cannot be processed by the network.
- The entry date was outside allowable settlement windows. The effective entry date must fall on a valid ACH processing day and cannot be a weekend, federal holiday, or otherwise non-settlement day.
- The effective date did not align with ACH processing rules. The date may not have matched the required timing for the SEC code used or did not allow sufficient lead time for processing.
Sending ACH Payments with Slash
You can send domestic or international ACH payments using Slash by following these steps:
- Navigate to the Payments dashboard and click Transfer Funds in the top-right corner.
- Select a recipient using saved contact and banking information, or add a new recipient by entering their contact and bank details.
- Choose the Slash account you want to use as the payment source, select ACH Transfer as the payment method, choose the destination bank account, and enter the payment amount (in USD).
- Optionally, send the recipient an email confirmation with a payment description. You can also add a memo with internal notes that are visible only to you and other Slash account administrators.
- Review the recipient's bank name, account number, and ACH routing number to ensure the payment details are correct.
- Once all information is confirmed, click Send Payment.
Slash offers 24/7 support by phone and email to help resolve any issues with sending payments. You can also improve how you manage ACH transfers by scheduling recurring ACH payments, receiving low-balance notifications, and tracking returned payments alongside other transactions. With Slash, you can view all account balances, ACH activity, and transfers in one centralized dashboard.







