Amegy Bank NACHA file requirements
Amegy Bank accepts NACHA-format ACH files through Treasury Internet Banking (Zions platform). The bank calls the feature "ACH origination". Here is what its published documentation requires.
Independent documentation. Not affiliated with or endorsed by Amegy Bank.
Before you upload, run the file through the free ACH file validator. It checks the structural rules and Amegy Bank's documented quirks in your browser; the file never leaves your computer.
How Amegy Bank ACH file upload works
- Amegy is part of Zions Bancorporation and runs the shared Treasury Internet Banking platform.
- Cutoffs: files by 5:30 pm CT at least two days before the effective date; same-day by 12:00 pm CT; reversals by 5:30 pm CT within 5 business days.
- Prefunding, where the agreement requires it, debits the offset account 2 days before processing, credits only.
- Prenotes are optional; if sent, at least 3 banking days before the first live entry.
- Reversals must carry the word REVERSAL in the company entry description.
- Caution: the guide still states a $25,000 same-day cap. Nacha raised the same-day limit to $1 million per entry in 2022; the document predates that. Confirm current limits with the bank.
Source: Transcribed from the bank's published service guide; field layouts follow the Nacha standard: Amegy Bank ACH Originator Quick Start Guide (checked July 2026); operations guide without field layouts. Reference. Banks change their requirements; your bank agreement and portal are the authoritative reference.
What to confirm with your Amegy Bank treasury contact
Four values are assigned per customer and only the bank can tell you them: your Company ID (often not just your EIN), the exact immediate origin value they expect in the file header, whether your agreement is set up for balanced or unbalanced files, and your cutoff times and settlement option. Get them in writing before the first upload.
Building the file
Most accounting software, including QuickBooks and Sage 50, cannot export a NACHA file directly. If your system exports one and Amegy Bank still rejects it, the validator will usually name the exact line and field. If the reason will not yield, the format setup service works it out with you. This software formats and checks files only. It moves no money; funds move solely through your own bank under your agreement with them.