An ABA file is a plain-text payment file used for Australian Direct Entry payments. You can open one in a text editor, but the fixed-width records are difficult to read and an accidental edit can make the file invalid. The simplest option is a purpose-built viewer that separates the header, payments, and totals into readable fields.
Open an ABA file with an online viewer
- Open the ABA File Viewer.
- Drop your
.abafile into the upload area, or choose it from your device. - Review the descriptive record, transaction rows, and file total record.
- Confirm that the payment count and totals match what you expected.
The viewer processes the file locally in your browser. The original file is not modified, so viewing it cannot change the amount, BSB, account number, or lodgement reference.
What you will see inside the file
Most ABA files contain three kinds of records:
- Descriptive record: identifies the user, financial institution, processing date, and file description.
- Detail records: contain the BSB, account number, transaction code, amount, account title, lodgement reference, and trace details for each payment.
- File total record: contains the transaction count and control totals used to check that the file is complete.
ABA is a fixed-width format. Each field occupies an exact character range rather than being separated by commas. A viewer translates those character positions into labelled columns.
Westpac's guide to importing ABA payment files describes the same three-part structure and publishes common checks for BSBs, dates, and summary totals.
Can I open an ABA file in a text editor?
Yes. Because an ABA file is plain text, applications such as Notepad, TextEdit, or Visual Studio Code can display it. Use a monospaced font and turn off word wrapping so that the field positions remain aligned.
This method is useful for a quick technical inspection, but it has two drawbacks:
- Fields are not labelled, so values can be misinterpreted.
- Saving the file may change its line endings, encoding, spacing, or final newline.
If the file is destined for a bank, avoid saving it from a general-purpose text editor unless you understand the ABA specification and can validate the result afterwards.
Can Excel open an ABA file?
Excel may display an ABA file if you import it as fixed-width text, but opening it directly does not reliably map each field to a column. Account numbers and BSBs can also lose leading zeroes when treated as numbers.
For spreadsheet analysis, convert a copy of the file instead of renaming it to .csv.
What if the ABA file will not open?
A viewer may reject a file when a record is missing, a line has the wrong length, or the content does not follow the expected Direct Entry structure. Do not assume that changing the extension will repair it.
Run the file through a validator to identify the exact record and field that needs attention. Typical problems include malformed BSBs, invalid transaction codes, amounts outside the permitted field width, and totals that do not reconcile.
Is it safe to open an ABA file online?
ABA files can contain sensitive payment information. Before using any online service, check how it handles uploads, whether files are retained, and whether processing happens on the server or on your device.
The tools on this site process ABA content in your browser. Even so, follow your organisation's data-handling policy, keep the source file in a secure location, and avoid sharing screenshots that expose account details.
CommBank similarly recommends that payment files—particularly payroll files—be kept in a secured network directory with restricted access.
Next step
If you only need to inspect the file, use the viewer. If you need to diagnose a rejected or malformed file, validate it first and then make corrections with the ABA File Editor.
