Fifth Third Bank
Describes the fixed-width IDX file format used by Fifth Third Bank, including payment (type 5) and invoice (type 6) record layouts, field positions, and key parsing considerations.
Fifth Third Bank — IDX format
How to identify this file: A single flat text file. Each line starts with either 5 (payment record) or 6 (invoice record). Lines starting with 5 are always followed by one or more 6 lines for that check's invoices.
Payment Record (Type "5") – Field Mapping Documentation
Record Identifier
Located at position 0
Fixed value: "5"
Identifies the record as a payment record
Business Date
Located at positions 1–8
Format: yyyyMMdd
Lockbox Number: Located at positions 9–14
Batch Number: Located at positions 15–19
Transaction Sequence: Located at positions 20–22
Cheque Amount:
Located at positions 23–34
Fixed length of 12 characters
Last 2 digits represent cents
Decimal is inserted during parsing
Check Number / Serial: Located at positions 35–44
Routing Number: Located at positions 45–53
Account Number: Located at positions 54–67
Image File Name:
Located at positions 68–147
Fixed length of 80 characters
Invoice Record (Type "6") – field mapping documentation
Record Identifier
Located at position 0
Fixed value: "6"
Identifies the record as an invoice record
Business Date
Located at positions 1–8
Format: yyyyMMdd
Lockbox Number: Located at positions 9–14
Batch Number: Located at positions 15–19
Invoice Sequence: Located at positions 20–22
Image File Name:
Located at positions 45–124
Fixed length of 80 characters
Key considerations
Format type: Fixed-width, positional — single file
Keyed-in (remittance data)? No — invoice records contain image references only, no keyed invoice number or amount
Image files? Referenced by file name in both record types
What is parsed: Check amount, routing, account, check number, lockbox number, batch, business date, image references
What is not parsed: Invoice number, invoice amount (image path present but no keyed data)