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When a Check Shows Up Twice
ACH payments often replace the need to handle physical checks, offering a faster and more efficient way to process transactions. In some cases, a paper check is scanned and converted into an ACH entry—saving time and reducing paperwork. But if the original paper check is also deposited through traditional banking channels after being converted, it creates a conflict.
That’s exactly what ACH Return Code R37 is signaling.
Let’s walk through what R37 – Source Document Presented means, why it happens, and how you should handle it to keep your payment process clean and compliant.
What Does ACH Return Code R37 Mean?
ACH Return Code R37 stands for:
“Source Document Presented.”
Here’s the NACHA definition:
R37 – Source Document Presented: The paper check that was used to create an ACH entry has also been presented separately to the banking system for payment.
In plain English: the same check was processed twice—once electronically through ACH, and once physically through traditional check clearing.
This triggers a return because banks and the ACH network do not allow duplicate collection of the same check.
How Does This Happen?
R37 returns usually occur when:
A business scans and submits a check electronically, but the customer or business also deposits the physical check
Employees misunderstand the process and deposit the paper check after it’s been electronically processed
Customers accidentally deposit the original check via ATM or mobile deposit apps
Paper checks are mistakenly reprocessed after a failed or reversed ACH conversion attempt
Since the ACH system and traditional check clearing networks don’t automatically “talk” to each other about scanned items, it’s up to banks to detect and reject duplicate presentations like this.
How to Handle ACH Return Code R37
If you receive an R37 return, here’s what to do:
1. Review the Transaction
Look at the ACH entry in question and verify which check was converted. Confirm that the paper check wasn’t also deposited or presented separately.
2. Check for Duplicate Collections
If you received funds through ACH and then received the same amount through traditional check deposit, the bank or your ACH provider may reverse one of them to prevent overpayment.
3. Contact the Customer (If Necessary)
If it looks like your customer or client accidentally redeposited the check (especially through a mobile app), let them know about the error and confirm the correct payment status.
4. Work With Your ACH Provider or Bank
Coordinate with your payment processor or financial institution to ensure the transaction is properly adjusted and that you are not holding duplicate funds.
How to Prevent R37 Returns in the Future
You can reduce the risk of R37 errors by tightening your check-handling process:
Communicate clearly to customers that once a check is accepted and processed electronically, they should not re-deposit it
Mark checks as “Electronically Processed” once they’re scanned
Securely store or destroy original checks after successful ACH conversion (following your processor’s retention guidelines)
Train your staff on proper handling of converted checks and ACH entries
Use ACH processing software that helps track and manage check conversions to avoid confusion
Simple steps like these can help prevent misunderstandings and double-processing.
Get ACH Processing With Durango
ACH Return Code R37—“Source Document Presented”—means the original paper check tied to an ACH conversion was also presented separately for deposit. It’s not a technical glitch or a fraud flag—it’s a conflict between two payment systems trying to process the same check.
At Durango Merchant Services, we help businesses handle every part of ACH processing, including managing check conversions, preventing returns, and setting up smart operational procedures. Whether you’re handling occasional check payments or running large batch deposits, we’re here to help make the process smoother.
