In Australia, bulk payments such as payroll and supplier runs travel through the Bulk Electronic Clearing System (BECS), also known as Direct Entry. Business banking platforms like CommBiz, Westpac Live, NAB Connect and ANZ Transactive accept them as an ABA file, also called a Cemtex file after its original designer. It is a plain text file with fixed-width lines. Here is how it is built.
Three kinds of line, each exactly 120 characters
| Type | What it holds |
|---|---|
0 descriptive record | One per file: reel sequence 01, your bank's 3-letter code (e.g. CBA, WBC, NAB, ANZ), your user name (26), your 6-digit Direct Entry User ID, a description such as PAYROLL (12) and the processing date as DDMMYY. |
1 detail record | One per payment: BSB as NNN-NNN, account number right-aligned in 9 characters, an indicator (normally blank), a 2-digit transaction code, the amount in cents (10 digits), the account name (32), the lodgement reference the payee sees (18), a trace BSB and account (yours, used for returns), your remitter name (16) and withholding tax (8 zeros in most files). |
7 file total record | 999-999, then the net total, the credit total and the debit total (10 digits each, in cents) and the count of type-1 lines. |
Lines usually end with CR LF. A single extra space or a missing one shifts every field after it, which is why hand-edited ABA files fail so often.
A tiny example
0 01CBA Example Pty Ltd 301500PAYROLL 061026
1082-902987654321 530000215000Jane Citizen PAY OCT W1 062-000 12345678Example Pty Ltd 00000000
7999-999 000021500000002150000000000000 000001(The lines above are trimmed; real lines are padded with spaces to 120 characters.)
Transaction codes
- 53 pay (salary and wages): the usual code for payroll.
- 50 general credit: suppliers, refunds and most other payments.
- 13 externally initiated debit: used for the balancing line, or by approved direct debit users.
- 51, 52, 54 to 57 are special credit types (pensions, dividends and so on) that few businesses use.
Balanced or unbalanced?
Most banks want an unbalanced file containing only your credits; they debit your account for the total themselves. Some ask for a self-balancing file, which ends with a debit line (code 13) to your own account for the total, so credits equal debits. Check your bank's guide before choosing.
Common reasons a bank rejects the file
- A line that is not exactly 120 characters.
- A BSB without the hyphen, or an account number longer than 9 digits.
- Totals or the record count in the type-7 line that do not match the detail lines.
- A wrong Direct Entry User ID or bank code in the header. Your bank tells you which to use.
- Characters outside the plain character set, such as curly quotes or emoji in names.
PayBatchKit's ABA generator pads every field, recomputes the totals and checks BSBs and accounts in your browser. Our tests re-read every file with an independent parser. Always check the bank's preview before you approve the payment run.
Sources
Related guides
Published 2026-10-02 by Karuna Labs. Our tools check file structure and checksums; always review outputs (and payment files in your bank's preview) before relying on them. This is general information, not financial, tax or legal advice.