Merge batches from multiple ACH files and rebuild file controls. Free, no signup, and your file is processed locally in your browser.
Primary topic: ACH file merge tool
The ACH file merge tool combines complete batches from multiple compatible NACHA files into one output file. Use this ACH file merge tool as a practical first step, then review its results carefully. do not merge unrelated originators or bank configurations unless your ODFI has approved that arrangement.
A reliable ACH file merge tool workflow starts by confirming the business purpose before changing or exporting any data. This page is designed for combines complete batches from multiple compatible NACHA files into one output file. It performs the supported work locally, so the source does not need to be sent to a conversion service. Use the ACH file merge tool with an approved source and a clearly defined expected result.
Start with two or more ACH files whose origin, destination and processing settings can validly share one file. Work from a copy, preserve leading zeros and remove unrelated report headings or totals that could be mistaken for transaction data.
Use the on-page controls, then compare the displayed batch count, entry count, total debits and total credits with the source expectation. Investigate warnings instead of assuming that a downloadable result is correct.
The expected result is one merged ACH file with renumbered batches and rebuilt file-level counts, hashes, totals and padding. Before transmission or downstream import, review compatibility warnings, duplicate trace numbers, effective dates, SEC codes, batch totals and final file controls, save the source separately and follow your organization’s approval process.
Confirm that the selected input really contains two or more ACH files whose origin, destination and processing settings can validly share one file. A renamed extension does not convert a spreadsheet, PDF or binary export into a valid ACH-related source.
Compare entries one batch at a time. Missing rows, duplicated rows, amount scaling, debit-versus-credit selection and malformed addenda can all change counts or monetary totals.
Format validation does not verify enrollment or bank policy. do not merge unrelated originators or bank configurations unless your ODFI has approved that arrangement. Ask the ODFI for the rejection code and compare it with the company profile, identifiers and processing date.
It combines complete batches from multiple compatible NACHA files into one output file. The ACH file merge tool processes the data locally in your browser and does not require an account.
It needs two or more ACH files whose origin, destination and processing settings can validly share one file. Files remain on your device during processing.
You will get one merged ACH file with renumbered batches and rebuilt file-level counts, hashes, totals and padding. Review the result before using it in an operational workflow.
Check compatibility warnings, duplicate trace numbers, effective dates, SEC codes, batch totals and final file controls. Also remember that do not merge unrelated originators or bank configurations unless your ODFI has approved that arrangement.
No. Processing creates a separate result in browser memory and leaves the source file unchanged. Keep the original as the audit baseline until the new output has been reviewed and accepted.
Confirm that the files share compatible originator and processing settings, then review compatibility warnings, duplicate trace numbers, effective dates, SEC codes, batch totals and final file controls. Do not rely on matching filenames or creation dates alone.
When the tool creates a new ACH output, it rebuilds affected counts, hashes, debit and credit totals, batch controls, file controls, block count and padding from the resulting entries.
Preserve the source, review a preview, validate the output and obtain any required approval before transmission. do not merge unrelated originators or bank configurations unless your ODFI has approved that arrangement.
Technical explanations are checked against these primary sources. Bank-specific requirements can be narrower than general format guidance.
Sources reviewed August 20, 2026. Nacha owns and maintains the linked materials.
ACH files use the NACHA fixed-width format: every record is 94 characters, files contain one or more batches, and control records reconcile entry counts, routing-number hashes, debits and credits. Always confirm bank-specific settings with your financial institution before uploading a production file.