ATO Simpler BAS (G1, 1A, 1B) & 47% No-ABN Withholding Guide for Australian Sole Traders (2026–27)

Short answer: Under the Australian Taxation Office (ATO) Simpler BAS reporting method, GST-registered sole traders and tradies with annual GST turnover under $10 million only report three GST labels on their quarterly Business Activity Statement: G1 (Total Sales), 1A (GST on Sales), and 1B (GST on Purchases). Separately, under the PAYG No-ABN Withholding rules (TAA 1953 Schedule 1 Section 12-190), if a supplier bills more than $75 excluding GST ($82.50 including GST) without quoting a valid 11-digit ABN, the payer must withhold 47% and remit it to the ATO.

⚡ Instant ATO Simpler BAS (G1, 1A, 1B) & 11-Digit ABN Tax Invoice Calculator ($AUD): Calculate your quarterly 10% GST and income tax in the interactive AUD Tax & BAS Calculator right below, save your first 5 ABN Tax Invoices or Bunnings dockets in the iCloud Web Workspace (5 Free Saves) (or click 🔗 Embed / CSV Template), explore the AU/NZ Tradie & Sole Trader App Store Edition and No-Subscription Bookkeeping Edition, or Download Keel Free on the App Store ($0/mo) (au-nz-tradies).

Whether you are an electrician, plumber, chippy, landscaper, or freelance consultant operating under a sole trader ABN, two ATO compliance rules determine how much cash stays in your bank account every quarter: how you calculate Simpler BAS (G1, 1A, 1B) on a Cash basis, and how you protect your invoices from the 47% No-ABN Withholding trap.

Below is the official ATO Simpler BAS and No-ABN Withholding guide for the 2026–27 income year. For broader context, see our complete guide to doing a BAS, ATO tax invoice requirements ($82.50 & $1,000 rules), ATO $82.50 docket & logbook rules, and how to invoice as a sole trader in Australia.

What is ATO Simpler BAS and who qualifies in 2026–27?

Simpler BAS is the default Goods and Services Tax (GST) reporting method for Australian small businesses—including all GST-registered sole traders—with an annual GST turnover of less than $10 million. Instead of completing the legacy 7-box GST worksheet (G1, G2 export sales, G3 other GST-free sales, G10 capital purchases, G11 non-capital purchases, 1A, and 1B), Simpler BAS requires only three GST figures each quarter in myGov or Online services for business:

Simpler BAS Label	Official ATO Name	What Sole Traders & Tradies Include Here	How to Calculate It (10% Australian GST)
Label G1	Total sales	Total gross business income for the quarter (choose GST-inclusive or GST-exclusive consistently; include taxable sales, GST-free sales, and input-taxed sales, but exclude private sales)	Sum of all customer invoices paid during the quarter (if on Cash accounting)
Label 1A	GST on sales	Total 10% GST you collected from customers on taxable supplies during the quarter	Taxable Sales (incl. GST) ÷ 11 (rounded down to nearest whole dollar)
Label 1B	GST on purchases	Total 10% GST credits on eligible business tools, materials, ute expenses, and subcontractor tax invoices (where you hold a valid Tax Invoice for purchases over $82.50 incl. GST)	Business portion of GST-inclusive taxable purchases ÷ 11 (rounded down to nearest whole dollar)
Label T1 / 5A (if applicable)	PAYG income tax instalment	Pre-payment towards your end-of-year individual income tax return (either ATO pre-filled instalment amount T8 or instalment rate T2 × T1 instalment income)	See PAYG instalments explained
Label W1 / W2 / W4 (if applicable)	PAYG tax withheld	Wages paid (W1), tax withheld from employees (W2), or 47% withheld from suppliers who did not quote an ABN (W4)	Remitted alongside your net GST

Why Simpler BAS saves tradies hours: Under Simpler BAS, you no longer have to split a $4,500 tool trailer purchase (G10 capital) from a $320 Bunnings timber docket (G11 non-capital) on the BAS form itself—both go straight into Label 1B.

Why do 95% of Australian sole traders choose Cash over Accrual GST accounting?

When you register for GST in Australia (mandatory at $75,000 annual turnover, or from dollar one for rideshare/taxi drivers), the ATO lets small businesses with turnover under $10 million choose between two GST accounting methods:

Feature / Cash Flow Impact	Cash Basis (Recommended for Sole Traders)	Non-Cash / Accrual Basis
When do you report GST on sales (1A)?	Only in the quarter the client actually pays your invoice into your bank account	In the quarter you issue the invoice, even if the builder or client takes 60 days to pay
When do you claim GST credits on purchases (1B)?	In the quarter you pay the supplier docket or trade account (and hold a valid Tax Invoice over $82.50)	In the quarter you receive the supplier’s tax invoice, even before paying it
Unpaid Invoice Risk	Zero — you never hand over 10% GST to the ATO out of your own pocket on an unpaid invoice	High — if you issue a $22,000 incl. GST roofing invoice on 28 September and get paid in November, you still owe $2,000 GST on your Q1 BAS (28 October)

How do you calculate a quarterly Simpler BAS in $AUD (worked example)?

Suppose Liam is a GST-registered sole trader plumber in Brisbane using Simpler BAS on a Cash basis for Quarter 1 (1 July – 30 September 2026):

1. Invoices Paid by Clients in Q1 (G1 & 1A):
   • Liam issued $49,500 (incl. GST) of invoices in Q1, of which $44,000 (incl. $4,000 GST) was actually paid into his account before 30 September. An unpaid $5,500 invoice issued on 27 September rolls into Q2 because he uses the Cash basis.
   • Label G1 (Total Sales, GST-inclusive): $44,000
   • Label 1A (GST on Sales): $44,000 ÷ 11 = $4,000
2. Business Purchases & Dockets Paid in Q1 (1B):
   • Reece Plumbing & Bunnings Trade supplies (all with valid 11-digit ABN Tax Invoices): $13,200 incl. GST ($1,200 GST credit).
   • Commercial work ute diesel, servicing & insurance (100% business use): $3,300 incl. GST ($300 GST credit).
   • ASIC business name renewal fee ($42 — GST-free government fee): $0 GST credit.
   • Public liability insurance ($1,100 total, where $100 is state stamp duty and $90.91 is GST on the Tax Invoice): $90 GST credit (always read the exact GST line on insurance invoices because stamp duty is GST-free).
   • Label 1B (GST on Purchases): $1,200 + $300 + $0 + $90 = $1,590
3. Net GST Payable to the ATO (1A − 1B):
   • $4,000 − $1,590 = $2,410 due by 28 October 2026.

What is the ATO 47% No-ABN Withholding rule (and the $75 ex-GST threshold)?

Under Taxation Administration Act 1953 Schedule 1 Section 12-190, the No-ABN Withholding rule works in both directions for a sole trader:

1. Protecting Your Own Invoices From 47% Withholding:
   • Whenever you invoice another business, builder, strata manager, or commercial client for more than $75 excluding GST ($82.50 including GST), your invoice must clearly display your active 11-digit ABN.
   • If your ABN is missing, invalid, or cancelled on ABN Lookup, the business paying you is legally required by the ATO to withhold 47% (the top marginal tax rate of 45% plus 2% Medicare levy) from your payment and send it to the ATO under BAS Label W4.
2. When You Pay a Subcontractor Who Has No ABN:
   • If a subcontractor bills you more than $75 ex-GST and does not quote an ABN, you must check whether they qualify for the ATO Statement by a supplier (NAT 3346) exemption (for example, an individual selling a private second-hand item).
   • If they are operating a business and still do not provide a valid ABN within 28 days, you must withhold 47% and report it at Label W4 on your BAS (and include the subcontractor in your TPAR report if you are in building and construction).

How does Keel compare with Xero and MYOB for Simpler BAS & ABN invoicing?

Feature	Xero AU (Ignite / Grow / Comprehensive)	MYOB Business Lite / Pro	Keel ($0/mo AU Sole Trader Edition)
Monthly Price ($AUD)	$35 to $95+/month ($420–$1,140/year after July price increases)	$34 to $63+/month	$0/mo Core App (No mandatory monthly subscription)
11-Digit ABN & 10% GST Tax Invoices	Yes	Yes	Yes — enforces 11-digit ABN, $82.50 / $1,000 ATO Tax Invoice rules & Non-GST mode
Simpler BAS (G1, 1A, 1B) Summary	Yes	Yes	Yes — instant Cash-basis G1, 1A & 1B totals ready to type into myGov for free
Thermal Docket OCR & 91c/km Ute Logbook	Requires Hubdoc + separate logbook app	Limited	Yes — built-in on-device Apple Vision Docket OCR + 91c/km & 12-week ATO logbook

Frequently asked questions

What are the three GST labels on a Simpler BAS in Australia?

Under the ATO’s Simpler BAS method (available to businesses and sole traders with GST turnover under $10 million), you only complete Label G1 (Total sales), Label 1A (GST on sales), and Label 1B (GST on purchases) in the GST section. You do not need to fill in G2 (export sales), G3 (other GST-free sales), G10 (capital purchases), or G11 (non-capital purchases).

Why is there no GST credit on some insurance, bank fees, or ASIC registration bills?

In Australia, residential rent, bank interest and account fees, ASIC business name fees, council rates, motor vehicle registration TAC/CTP components, and state stamp duty on insurance policies are either GST-free or input-taxed. Never divide an entire insurance or rego renewal bill by 11—always copy the exact GST amount printed on the supplier’s tax invoice into your 1B calculation.

When does the 47% No-ABN withholding rule apply in Australia?

If a business pays a supplier or subcontractor more than $75 excluding GST ($82.50 including GST) for goods or services in Australia and the supplier does not quote a valid 11-digit ABN on their invoice (and does not provide a valid ATO Statement by a supplier NAT 3346 form), the payer must withhold 47% of the payment and remit it to the ATO at BAS Label W4.

Can I lodge my quarterly Simpler BAS for free without paying for Xero?

Yes. Every Australian sole trader can lodge their quarterly Simpler BAS for $0 directly through myGov (linked to the ATO) or Online services for business using the three figures (G1, 1A, 1B) generated from their paid invoices and expense dockets, without needing a paid cloud accounting subscription.

Should a sole trader report G1 Total Sales including or excluding GST on Simpler BAS?

The ATO allows you to report Label G1 (Total sales) either including GST or excluding GST, provided you tick the matching box on the BAS form and use the same method consistently each quarter. Most sole traders using Simpler BAS report G1 including GST so it matches the total cash banked from customer invoices.

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