An ABA file is a fixed-width text file used to submit batches of Australian Direct Entry transactions to a bank. Businesses commonly generate ABA files from payroll or accounting software and upload them through business banking to pay employees, suppliers, or other recipients.
AusPayNet describes Direct Entry as part of the Bulk Electronic Clearing System (BECS), which it administers for electronic debit and credit payment instructions. AusPayNet also identifies BECS as Australia's primary account-to-account payment system.
The format is also called the Australian Bankers Association format, Direct Entry format, or BECS file format. An ABA file normally uses the .aba extension, although the filename itself does not determine whether the contents are valid.
What is an ABA file used for?
Instead of entering every payment manually in online banking, a business can prepare a batch in its accounting, payroll, or payment system. That system exports one ABA file containing the batch. An authorised user then reviews and uploads it through the organisation's bank.
Common uses include:
- employee payroll;
- supplier and contractor payments;
- refunds and customer disbursements;
- direct credits to multiple Australian bank accounts; and
- some authorised direct-debit workflows.
An ABA file is a payment instruction file. Creating or viewing the file does not send money. Processing only begins after the file is submitted and authorised through the relevant bank.
What is inside an ABA file?
ABA uses fixed-width records. Each line has a defined purpose, and every field must occupy a particular character range. Spaces and leading zeroes can therefore be meaningful.
ANZ's published ABA guidance confirms that the format is fixed width and consists of header, detail, and file-total sections.
Descriptive record
The first line describes the batch. It normally includes the financial institution abbreviation, the name and number of the approved user, a description, and the requested processing date.
Detail records
Each payment has its own detail record. Depending on the transaction, a record can include:
- the destination BSB and account number;
- a transaction code;
- the amount in cents;
- the recipient's account title;
- a lodgement reference shown to the recipient; and
- trace account details used to identify the originator.
File total record
The final line summarises the batch. It includes control totals and the number of detail records. A bank or validator can compare these values with the detail records to detect incomplete or internally inconsistent files.
What does an ABA file look like?
Viewed as raw text, an ABA file looks like tightly packed rows of letters, numbers, and spaces. It is not a spreadsheet, even though each payment contains field-like data. Renaming the file to .csv does not convert it and may hide important formatting requirements.
Are ABA files the same for every bank?
Australian banks generally accept files based on the Direct Entry format, but the values you must use—such as the financial institution abbreviation, user ID, trace account, and processing rules—come from your bank or payment facility.
Do not copy these originator details from an unrelated sample file. Ask your bank which values apply to your account and confirm its upload and authorisation requirements.
Is an ABA file secure?
The format itself is plain text and is not encrypted. Anyone with access to the file may be able to read account and payment information. Store ABA files in an approved location, restrict access, and transfer them only through authorised systems.
The ABA tools on this site process file contents locally in the browser, but your organisation's security and privacy policies still apply.
How do I know whether an ABA file is valid?
A valid file needs more than a .aba extension. Its record types, character widths, field formats, transaction codes, dates, and totals must comply with the expected structure. It must also contain the originator details supplied by your financial institution.
Passing a format check does not guarantee that a bank will accept or process the file. The bank can still reject incorrect user details, unavailable processing dates, duplicate batches, account permissions, or other institution-specific conditions.
How can I create an ABA file?
Many accounting and payroll platforms can export ABA directly. If your payments are already in Excel or CSV, you can map the spreadsheet columns to ABA fields and generate a formatted file. Always verify the bank-provided user and trace details before uploading the result.
