Simpler BAS reporting is the Australian Taxation Office’s streamlined method for the GST section of your Business Activity Statement. If your GST turnover is under $10 million, you fill in just three GST labels: G1 for total sales, 1A for GST on sales, and 1B for GST on purchases.1Australian Taxation Office. Simpler BAS – Goods and Services Tax The ATO has already moved most eligible businesses onto this method automatically, so for many small businesses the change happened without any action on their part.
Who Qualifies
Eligibility turns on GST turnover, not aggregated turnover. GST turnover is your gross business income minus any GST included in that income. Sit below $10 million and you qualify.1Australian Taxation Office. Simpler BAS – Goods and Services Tax
You can check which method you’re on by logging into your online business account through myGov or by asking your registered tax agent. If turnover climbs to $10 million or above, phone the ATO on 13 28 66 to update your turnover; you’ll move to full reporting from the start of the next financial year. If turnover falls back under the threshold, contacting the ATO shifts you to Simpler BAS from your next tax period.2Australian Taxation Office. GST Reporting Methods
The Three Labels You Fill In
The whole GST section comes down to three fields.
G1 — Total sales. All your gross sales for the period: taxable sales, GST-free sales, and input-taxed sales. If you use the calculation worksheet method, include the GST component in your taxable sales figure at G1. If you use the accounts method and report GST-exclusive amounts, leave the GST component out.3Australian Taxation Office. Step 1: Sales
1A — GST on sales. The total GST collected on your taxable sales during the period.4Australian Taxation Office. Simpler BAS GST Bookkeeping Guide
1B — GST on purchases. The GST included in the price of your business purchases, which you claim back as credits.4Australian Taxation Office. Simpler BAS GST Bookkeeping Guide
That’s the entire GST section. The old full reporting method required additional labels like G2 for export sales, G10 for capital purchases, and several other sub-categories that forced you to classify every transaction. Simpler BAS drops all of that from the form. Your accounting software or manual ledger still needs to track the underlying detail in case of an audit, but you no longer break it out at lodgment.
What Simpler BAS Doesn’t Change
Only the GST section is streamlined. If you have employees, PAYG withholding labels still appear on the same BAS. W1 covers total salary and wage payments; W2 covers the tax withheld from those payments. If you pay a supplier who doesn’t provide an ABN, you withhold 47% of the payment and report it at W4.5Australian Taxation Office. Pay as You Go (PAYG) Withholding Some businesses also have PAYG instalment obligations for their own income tax, which appear separately on the BAS. The form is a combined statement covering several tax types, and Simpler BAS only touches the GST part.
Cash or Accrual: When a Transaction Lands
Your accounting method decides when a sale or purchase feeds into G1, 1A, or 1B. Under the cash method, you report GST when you actually receive payment from a customer or pay a supplier. Under the accrual method, you report GST when you issue or receive an invoice, regardless of when the money moves.6Australian Taxation Office. Choosing an Accounting Method for GST
The difference matters more than people expect. A business using accrual accounting that invoices $50,000 in June but isn’t paid until August reports that GST in the June quarter. On cash accounting, it falls into the September quarter. Switching methods without understanding the timing impact leaves transactions either double-counted or missed.
When Your BAS Is Due
Most small businesses lodge quarterly. The due dates each year are:
- Quarter 1 (July–September): 28 October
- Quarter 2 (October–December): 28 February
- Quarter 3 (January–March): 28 April
- Quarter 4 (April–June): 28 July
If a due date lands on a weekend or public holiday, the deadline shifts to the next business day. Lodging online gets you an extra two weeks for quarters 1, 3, and 4. Quarter 2 already includes a built-in one-month extension, so the online bonus doesn’t apply there. Businesses using a registered tax or BAS agent may get additional time.7Australian Taxation Office. Due Dates for Lodging and Paying Your BAS
Businesses reporting monthly (required at $20 million or more in GST turnover, optional otherwise) lodge on the 21st of the following month.7Australian Taxation Office. Due Dates for Lodging and Paying Your BAS
How to Lodge
The most common route is the ATO’s online business portal, accessed through myGov. Sole traders reach the same lodgment system through their personal tax account.8Australian Taxation Office. Business Activity Statements (BAS)
Most modern accounting packages support Standard Business Reporting (SBR), which sends your BAS data straight from your bookkeeping software to the ATO with no re-keying.9Australian Taxation Office. Using Standard Business Reporting If your books are current, it’s a one-click lodgment. A registered tax or BAS agent can also lodge on your behalf. After successful lodgment, you’ll get a confirmation number and a payment reference number (PRN) for any amount owed.
Fixing Mistakes on a Previous BAS
Errors split into two categories, and the rules differ for each. A credit error means you overpaid GST — for example, you reported a sale twice or forgot to claim a credit. A debit error means you underpaid: perhaps you left a taxable sale off your return or overclaimed credits.10Australian Taxation Office. Types of GST Errors
Credit errors are straightforward. You can fix them on your next BAS as long as you’re within the four-year review period, which runs from the day you lodged the original BAS.11Australian Taxation Office. Time Limit on GST Credits and Refunds There’s no dollar cap on credit error corrections.
Debit errors are tighter. You can correct them on a later BAS only if all three conditions are met:
- The error is within 18 months of the original BAS (or 12 months if your turnover is $20 million or more).
- The total of your debit errors is under $12,500 (for turnover below $20 million).
- The error wasn’t caused by deliberate disregard of the law or gross carelessness.
If a debit error falls outside those limits, you can’t adjust the next BAS. You need to go back and revise the original period. Reckless or intentional errors are treated seriously, and quietly correcting one on a later BAS when you’re not entitled to can make the problem worse.10Australian Taxation Office. Types of GST Errors
The GST Instalment Alternative
Simpler BAS isn’t the only streamlined option available under the $10 million threshold. Businesses that qualify can instead choose the GST instalment method, where the ATO sets a quarterly instalment amount and you lodge a single annual GST return.2Australian Taxation Office. GST Reporting Methods The instalment amount appears on each quarterly activity statement, so there’s no need to calculate the actual GST position quarter by quarter.
The annual return still uses G1, 1A, and 1B, plus a 1H label for the instalment amounts already paid. Instalments work well when turnover is stable and predictable; if sales fluctuate, you can end up overpaying or underpaying across the year. If you’re on instalments and would rather report actual GST amounts each quarter, contact the ATO to switch to Simpler BAS.2Australian Taxation Office. GST Reporting Methods