You get an email when a check draft (eCheck, EFT direct debit) is returned unpaid. You get a reason for each. Most of these reason codes you'll never see. Most are R01, insufficient. R03 and R04 may simply mean we entered an account number wrong.
You probably never need to know this, but DFI is their word for bank (depository financial institution): ODFI is originating bank (your bank), RDFI is receiving bank (the member's bank).
ACH Return Reasons
R01 Insufficient Funds
R02 Account Closed
R03 No Account/Unable to Locate Account
R04 Invalid Account Number
R05 Reserved
R06 Returned per ODFIs Request
R07 Authorization Revoked by Customer
R08 Payment Stopped or Stop Payment on Item
R09 Uncollected Funds
R10 Customer Advises Not Authorized
R11 Check Truncation Entry Return
R12 Branch sold to another DFI
R13 RDFI not qualified to participate
R14 Representment payee deceased or unable to continue
in that capacity
R15 Beneficiary of account holder deceased
R16 Account Frozen
R17 File record edit criteria
R18 Improper effective entry date
R19 Amount field error
R20 Non-Transaction Account
R21 Invalid company identification
R22 Invalid individual ID number
R23 Credit entry refused by receiver
R24 Duplicate entry
R25 Addenda error
R26 Mandatory field error
R27 Trace number error
R28 Routing number check digit error
R29 Corporate customer advises not authorized
R30 RDFI not participant in check truncation program
R31 Permissible return entry
R32 RDFI non-settlement
R33 Return of XCK entry
R34 Limited participation DFI
R35 Return of improper debit entry
R36 Return of improper credit entry
R40 Return of ENR entry by Federal Government Agency (ENR Only)
R41 Invalid transaction code (ENR Only)
R42 Routing number/check digit error (ENR only)
R43 Invalid DFI account number (ENR only)
R44 Invalid individual ID number (ENR only)
R45 Invalid individual name/company name (ENR only)
R46 Invalid representative payee indicator (ENR only)
R47 Duplicate enrollment
R50 State Law Affecting RCK Acceptance
R51 Item is Ineligible, Notice Not Provided, Signature not genuine
R52 Stop Payment on Item
R61 Misrouted return
R62 Incorrect trace number
R63 Incorrect dollar amount
R64 Incorrect individual identification
R65 Incorrect transaction code
R66 Incorrect company identification
R67 Duplicate return
R68 Untimely Return
R69 Multiple Errors
R70 Permissible return entry not accepted
R71 Misrouted dishonored return
R72 Untimely dishonored return
R73 Timely original return
R74 Corrected return
R80 Cross-Border Payment Coding Error
R81 Non-Participant in Cross-Border Program
R82 Invalid Foreign Receiving DFI Identification
R83 Foreign Receiving DFI Unable to Settle
Change Codes:
C01 Incorrect DFI Account Number
C02 Incorrect Transit/Routing Number
C03 Incorrect Transit/Routing Number and Incorrect DFI Account Number
C04 Incorrect Individual Name
C05 Incorrect Transaction Code
C06 Incorrect DFI Account Number and Incorrect Transaction Code
C07 Incorrect Transit/Routing Number, Incorrect DFI Account Number, and Incorrect Transaction Code
C08 Reserved
C09 Incorrect Individual Identification Number
C10 Incorrect Company Name
C11 Incorrect Company Identification
C12 Incorrect Company Name and Company Identification
C13 Addenda Format Error
C61 Misrouted Notification of Change
C62 Incorrect Trace Number
C63 Incorrect Company Identification Number
C64 Incorrect Individual Identification Number
C65 Incorrectly Formatted Corrected Data
C66 Incorrect Discretionary Data
C67 Routing Number Not From Original Entry Detail Record
C68 DFI Account Number Not From Original Entry Detail Record
C69 Incorrect Transaction Code