ACH File Converter

Merge NACHA Files

Combine compatible ACH batches into one NACHA file and rebuild file controls.

1

Select ACH files to merge

Review the combined file

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What is preserved from each input

Batch headers, entries, addenda, and batch controls remain grouped so payment relationships are not flattened or mixed.

File-level values rebuilt after merging

The output receives coherent creation metadata, batch numbering, file counts, entry counts, entry hash, debit and credit totals, block count, and type 9 padding.

Compatibility checks before combining batches

  • Confirm the same destination and transmission context.
  • Check duplicate files and duplicate payments.
  • Review effective dates and processing windows.
  • Ensure the ODFI accepts multiple companies or SEC codes in one file.

Reasons to keep files separate

Different banks, transmission deadlines, approvals, settlement models, or duplicate-risk controls can make separate delivery safer even when the records are structurally mergeable.

Questions about merging ACH batches

Can files for different banks be merged?

Do not assume so. File Header destination and bank transmission rules must be compatible.

Will merging detect duplicate payments?

Review duplicate warnings and source identities explicitly; structural merging alone cannot prove business-level uniqueness.

Are batch totals changed?

Batch contents stay grouped, while file-level totals and counts are rebuilt over all included batches.

Which authoritative sources support this page?

Technical explanations are checked against these primary sources. Bank-specific requirements can be narrower than general format guidance.

  1. Nacha ACH File Details — Official record-field guidance, including Batch Header SEC codes and addenda capabilities.
  2. Nacha ACH File Overview — Official explanation of files, batches, entries, controls, and batch grouping.
  3. Nacha: How ACH Works — Official overview of ACH participants, consumer and corporate payments, and authorization responsibilities.
  4. Nacha Operating Rules Topics — Current rule changes and implementation topics published by Nacha.

Sources reviewed August 20, 2026. Nacha owns and maintains the linked materials.