A .ach file is a data format used to move money between bank accounts, not a program you run

A .ach file is a text file that contains instructions for transferring money. ACH stands for Automated Clearing House, which is the system banks use to move funds electronically. You will not open it like a document or image — instead, you upload it to your bank's website or give it to someone else who needs to process the transfer.

Most people encounter .ach files in two situations: either your employer or payroll company sends you one to set up direct deposit, or you create one to send money to multiple people at once (like paying contractors or distributing refunds). The file itself is just plain text with account numbers, routing numbers, and dollar amounts formatted in a specific way that banks recognize.

Key Takeaways

  • A .ach file contains bank transfer instructions and must be uploaded to your bank's website or given to a payroll processor — you do not open it as a regular document.
  • Your employer or payroll company typically creates .ach files for direct deposit setup, while businesses create them to pay multiple people in one batch.
  • You need your bank's routing number and your account number to receive an ACH transfer, and you provide these to whoever is sending the file.
  • Most banks accept .ach files through their business portal, though some require you to use third-party payroll or accounting software instead.

How to receive money through a .ach file

If someone sends you a .ach file to deposit money into your account, you do not need to do anything with the file itself. The person or company sending it will upload it to their bank, and the transfer will land in your account automatically within one to two business days. You only need to provide your bank's routing number and your account number — the nine-digit code printed on the bottom left of your checks.

The most common reason you will receive a .ach file is for direct deposit. Your employer's payroll department creates one that tells the ACH system to move your paycheck from the company's bank account to yours on payday. You set this up once by filling out a form with your routing and account numbers, and then it repeats automatically every pay period without you touching the file.

How to send money using a .ach file

If you need to send money to multiple people — such as paying freelancers, distributing a refund, or processing payroll — you can create a .ach file and upload it to your bank. Most business checking accounts include this feature through the bank's website or mobile app. You will need the recipient's routing number, account number, and the amount to send to each person.

The process usually works like this: log into your bank's business portal, find the ACH or batch transfer section, enter each recipient's information and amount, review the total, and upload. Your bank will then process the file and send the money out. Some banks charge a small fee per transaction (typically 25 cents to a dollar), while others include ACH transfers free with a business account.

If you use accounting software like QuickBooks or payroll software like Gusto, those programs can create and send .ach files directly to your bank without you building the file manually. This is the easier route if you are already using that software.

What to do if you receive a .ach file you do not recognize

If someone emails you a .ach file and you are not expecting a transfer, do not open it or run it. A .ach file itself cannot harm your computer, but it is a signal that someone may be trying to trick you into authorizing a transfer. Delete the email and contact the sender through a phone number or email address you know is legitimate to confirm whether they actually sent it.

Scammers sometimes send .ach files claiming to be from your bank, a government agency, or a company you do business with. Real banks and government agencies will not email you a file to download. If you are unsure, call your bank directly using the number on the back of your card.

Opening a .ach file to view its contents

If you need to see what is inside a .ach file — to check account numbers, amounts, or recipient names — you can open it with any text editor. Right-click the file, select "Open with," and choose Notepad (Windows) or TextEdit (Mac). The file will display as plain text with rows of numbers and letters separated by commas or pipes.

The format is standardized but difficult to read without knowing the layout. Each line represents one transaction, and the numbers in each position mean something specific (routing number, account number, amount, date). If you need to edit a .ach file, it is safer to use your bank's portal or accounting software rather than editing the text directly, since a small mistake in formatting will cause the bank to reject the entire file.

Where .ach files come from and where they go

Your employer or payroll company creates .ach files. Your bank receives them. Accounting and payroll software can create them. But you, as an individual receiving a paycheck or a payment, almost never need to create one yourself. The file moves behind the scenes between financial institutions.

The only time a regular person creates a .ach file is if they run a small business and want to pay multiple people at once. Even then, most people use their bank's website or payroll software to do it, which handles the file creation automatically. You see the file name only if you download it for your records or if someone emails it to you by mistake.

Frequently Asked Questions

Can a .ach file give my computer a virus?

No. A .ach file is plain text and cannot execute code or install software. It is safe to open in a text editor to view its contents. However, if someone emails you a .ach file unexpectedly, it may be a sign of a scam, so treat the email itself with caution.

What is the difference between a .ach file and a wire transfer?

ACH transfers are slower (one to two business days) and cheaper, while wire transfers are faster (same day or next day) and more expensive. ACH files are used for routine payments like payroll and bill payments. Wire transfers are used when speed matters or for larger amounts.

Do I need to download a .ach file to receive direct deposit?

No. You fill out a form with your bank information, your employer uploads the .ach file to their bank, and the money appears in your account. You never handle the file yourself.

What should I do if my bank rejects a .ach file I tried to upload?

Banks reject files when account numbers are wrong, routing numbers do not match the bank, or the file format is corrupted. Contact your bank's support line with the file name and the error message you received. They can tell you what needs to be fixed.

Can I edit a .ach file in Excel?

Technically yes, but it is not recommended. Excel may reformat numbers or add extra characters that break the file. If you need to change information in a .ach file, use your bank's portal or the software that created the file originally.