Payroll Teams: Validate ACH Payroll Files Before Submission

A payroll run that fails at the bank means employees do not get paid on time. Drop the payroll file into NACHA Navigator before you send it: confirm the effective entry date lands on the right pay date, verify total debit and credit dollar amounts in the File Control record match your payroll register, and spot-check individual employee entries without counting characters in a text editor.

Key concepts: PPD (Prearranged Payment and Deposit) entries, effective entry date, batch control totals, and entry hash validation.

Banks & Credit Unions: Troubleshoot Rejected or Malformed NACHA Files

ACH operations staff regularly receive originated files that fail pre-processing edits: wrong record lengths, missing File Control records, invalid routing number check digits, or batches whose entry counts do not match their control records. NACHA Navigator turns the raw file into a color-coded, record-by-record breakdown so you can jump straight to the flagged batch — without exposing customer data to any external system.

Key concepts: record type codes, blocking factor and block count, entry hash, trace numbers, and check-digit validation of ABA routing numbers.

Treasury & Finance: Audit Entry Details, Batch Totals, and Control Records

Open the origination file and read the File Control record totals directly: total entry and addenda count, total debit dollars, total credit dollars. Batch Header records show the company name, company ID, and standard entry class for each batch, making reconciliation against an AP run fast and accurate.

Key concepts: transaction codes (22/27 checking credit/debit, 32/37 savings), company ID continuity, CCD vs. CTX entries, and file-level vs. batch-level control totals.

Fintech Developers: Learn and Debug the NACHA File Format

Building ACH origination means producing byte-perfect fixed-width files. NACHA Navigator doubles as an interactive reference: load the built-in sample, click through every field to see its exact position, length, and rules, then compare against your generated file to pinpoint off-by-one padding or justification bugs.

Key concepts: 94-character fixed-width records, field justification and padding rules, addenda records, trace number construction, and SEC codes (PPD, CCD, WEB, TEL, CTX).

Operations Teams: Generate ACH Reversal Files for Erroneous Entries

Nacha rules allow originators to reverse erroneous entries within five banking days of settlement. NACHA Navigator generates the reversal for you: load the original file, select the entries, choose the reason, and download a correctly balanced NACHA reversal file — transaction codes flipped, control totals recalculated, description set.

Key concepts: the five-banking-day reversal window, permissible reversal reasons, flipped transaction codes, and the required "REVERSAL" company entry description.

Compliance & Audit: Review ACH Origination Files

Because NACHA Navigator runs entirely in the browser, compliance teams can inspect origination files on their own machines without any data leaving the device — consistent with strict data-handling requirements. Document batch composition, originating company IDs, effective dates, and dollar totals, and trace any entry by its trace number.

Key concepts: originator identification, immediate origin and destination fields in the File Header, and trace number audit trails.

Frequently Asked Questions

What is a NACHA file?

A NACHA file is a fixed-width text file format defined by Nacha for submitting ACH payments in the United States. Every line is exactly 94 characters and represents a record: a File Header (type 1), Batch Headers (type 5), Entry Details (type 6), optional Addenda (type 7), Batch Controls (type 8), and a File Control (type 9).

How do I read or open a NACHA file?

A NACHA file is plain text, but interpreting it by counting character positions is slow and error-prone. A NACHA file viewer like NACHA Navigator parses each record type automatically, labels every field, and lets you click any field to see its meaning, position, and validation rules.

How do ACH reversals work?

An originator may reverse an erroneous entry within five banking days of the settlement date. The reversal must be for the full amount, flow in the opposite direction, and include "REVERSAL" in the company entry description. NACHA Navigator generates properly formatted reversal files from your original entries.

Is my ACH file data secure when I use NACHA Navigator?

Yes. NACHA Navigator parses your file entirely in your browser. The file is never uploaded to a server, never stored, and never transmitted over the network.

Why was my NACHA file rejected by my bank?

Common causes include incorrect record lengths (lines must be exactly 94 characters), unbalanced batch or file control totals, invalid routing number check digits, bad effective entry dates, missing blocking-factor padding, and malformed SEC codes.

Does NACHA Navigator cost anything?

No. NACHA Navigator is free to use for viewing, validating, and generating reversal files.