Guides
Your EOFY Survival Guide for Australian Small Business/Companies
9 September, 2025 · 5 mins
Understand GST and BAS in Australia with this quick guide. Learn how GST works, when to register, and how to lodge BAS to stay compliant with the ATO
Quick Summary:
- GST registration: Required if your annual GST turnover is $75,000 or more
- BAS due dates: Most small businesses lodge BAS quarterly, due 28 Oct, 28 Feb, 28 Apr, 28 Jul
- How to lodge: Submit your BAS online, via your ATO online services, a SBR-enabled software, or through your accountant
- Penalties: Late BAS lodgement can mean fines from $330 plus daily compounding interest
What is GST?
GST (Goods and Services Tax) is a 10% tax on most goods and services sold in Australia. If you're registered for GST, you're expected to charge it on sales, pay it to the ATO, and claim back the GST on your eligible business purchases.
Who needs to register for GST?
If your GST turnover hits $75,000 or more, you’ve got 21 days to register. In some cases, you’ll need to register no matter what you earn, like if you’re driving for Uber or doing other ride-share gigs. Earning less? You can still register voluntarily if it makes sense for your business. Got questions? Reach out to us in the app chat. ANNA can help you get registered.
What is a BAS?
A Business Activity Statement (BAS) is your regular tax check-in with the ATO. It’s where you report and pay GST, PAYG withholding (tax on wages), PAYG instalments (prepaid tax), and other business taxes. Most small businesses lodge it quarterly. See a sample.
What’s an IAS?
An Instalment Activity Statement (IAS) is like a mini BAS. It’s used to report and pay things like PAYG instalments or withholding tax. You’ll usually get one monthly from the ATO if you need to lodge it. See a sample.
So, what’s the difference between BAS and IAS?
Both are ATO forms used to report and pay business taxes but they serve different setups:
BAS is the full kit: GST, PAYG withholding, PAYG instalments, and more
IAS is the smaller version: no GST, just PAYG obligations.
Example Time:
Let’s say your business is registered for GST and lodges BAS quarterly. You’ve also got employees, so you’re withholding PAYG tax from their wages. If your payroll hits a certain threshold, the ATO might ask you to report PAYG withholding monthly, even if everything else stays quarterly. In that case, you’ll lodge a quarterly BAS for GST and PAYG instalments, and a monthly IAS just to handle PAYG withholding for your team.
Still Confused? Check out ‘Simpler BAS’
If your GST turnover is under $10 million, you only need to report 3 things under the “Simpler BAS” method:
G1 – Total Sales
1A – GST on Sales
1B – GST on Purchases
Great, so when is BAS due?
If you're on quarterly BAS, your due dates are below:
On monthly BAS? Pop into the app chat and give us a wave, we'll help you out.
Bonus: Lodging online? You could get up to 2 extra weeks, except for Q2 (1 Oct to 31 Dec), as the due date of 28 Feb already includes a Christmas extension.
Note: Due dates apply to both lodgement and payment. Stressed about remembering the dated? Your ANNA tax calendar has deadline reminders tailored just for you.
Quick Tips:
- Keep it Clean: No cents. No rounding up. Whole dollars only on IAS/BAS.
- Nothing to Report? Just lodge a NIL IAS/BAS through ANNA.
- Oops! Made a mistake? Fix it in your next BAS or lodge a revision. Use code 1A/1B to correct GST on sales/purchases.
- PAYG Instalment got you panicking? Too high? Just vary it (code T9, reason code T4). Overpaid last time? Claim a credit on B5.
Heads up: If your instalments are too low, the ATO may charge interest. - Stay on top of it: Keep solid records of sales and expenses. ANNA can help you by matching your transactions and keeping track of your uploaded evidence. You can also use ANNA to prepare your BAS.
- Stash that GST cash: Set aside GST as you go, your future self will thank you. Use ANNA pots (coming soon) and real time GST estimator (also coming soo) to automatically put money aside for GST payments.
Got questions? Reach out to us in the app chat. You can also find more info about GST/BAS on the ATO website.
Register a Company with ANNA
ANNA +Taxes is available for newly registered companies – first 1,000 customers get 6 months free. We auto-categorise your transactions and take care of your lodgements.
Register NowFrequently asked questions
How do I register for GST?
Hop on the ATO website. You’ll need an ABN first. ANNA can also help you get GST registered. Just message us in the app chat
What is GST turnover?
Your GST turnover is your total business income (not your profit), minus:
• GST included in sales to your customers
• Sales to associates that aren't for payment and aren't taxable
• Sales not connected with an enterprise you run
• Input-taxed sales you make
• Sales not connected with Australia
What’s the difference between cash and accrual reporting basis for GST?
• Cash: Report when money hits your bank account or leaves it
• Accrual: Report when invoices are issued/received, regardless of payment
Most small businesses go with cash to keep cash flow simple
How to calculate GST?
• To add GST, multiply the net price by 1.1
• To find the GST amount, divide the GST-inclusive price by 11
• To remove GST, divide the GST-inclusive price by 1.1
Example time:
If your product price is $100 (excluding GST):
• Add GST: $100 × 1.1 = $110 (price including GST)
• GST amount included: $110 ÷ 11 = $10
• Price without GST: $110 ÷ 1.1 = $100
If you’re using ANNA, our invoice generator and receipt capture tool will sort and allocate the GST for you. No stress, no spreadsheets
Got a simple GST calculator I can use?
You bet. Head over to Money Smart’s GST calculator. It’s quick, easy, and does the calculations for you. No brain strain required
If you’re using ANNA, our invoice generator and receipt capture tool will sort and allocate the GST for you - no calculator needed
Can I claim GST on everything I buy for my business?
Almost! But you’ll need:
To register for GST for your business
A valid tax invoice with the GST component clearly stated
The purchase to relate directly to your business
Some things (like basic foods, entertainment) are off-limits. Check the ATO website for more details
Just letting you know: The ATO is warning businesses not to mess around with fake or inflated GST refund claims. If it looks fishy, they’ll investigate and penalties aren’t pretty. Keep your records clean and your claims legit
How do I check if my business is GST-registered?
Search your ABN on the ABN Lookup or log in to your ATO account. Or, you guessed it, ask us in the app chat
How often do I need to lodge a BAS?
Most small businesses lodge quarterly, but it depends on your GST turnover. Less than $10 million? Quarterly is your default. Over $20 million? You’re in the monthly club. Check the ATO website for more details
How to do a BAS statement?
Here is cash basis BAS preparation steps simplified for you:
Step 1: Bank reconciliation
Match all transactions for the period to your bank statements and assign them to the right categories
Step 2: Check GST Codes
Verify GST is correctly applied to income and expenses for each transaction
Step 3: Review Payroll
Check payroll is up to date and PAYG withholding is accurate
Step 4: Check PAYG Instalments
Check your current BAS if there is a pre-filled PAYG instalment for this period
Step 5: Calculate BAS Amount
Add up GST collected on sales, subtract GST paid on expenses, then add PAYG withholding and any PAYG instalments to find the total BAS payable
How to lodge BAS online?
Log in to the ATO’s Online Services for Business using your myGovID. You’ll need to link your business on RAM (that’s the Relationship Authorisation Manager). Need help setting it up? Our New Company Setup Checklist has you covered
If you’re with ANNA, we can review and lodge your BAS for you, just give us a shout in the app chat
How do I pay the ATO?
You can pay via BPAY, credit card, Direct Debit or bank transfer. Using ANNA? Just pay with your ANNA business card. We’ll match the payment to your ATO bill, easy as that
Can’t find your BAS reference number? No stress, just message us in the app chat and we’ll track it down for you
Is ANNA a SBR-enabled software?
ANNA is not currently SBR-enabled, but we’re actively working on integrating Standard Business Reporting (SBR) functionality. We’re aiming to launch this capability by Q2 2026 to support seamless ATO BAS lodgements directly through the platform
Disclaimer:
This content is general information for small businesses. You can only use the document for your noncommercial purposes. In no event shall we be held liable for any claims arising due to, or dependencies on the accuracy and completeness of the content provided. ANNA+Taxes does not provide personal or professional financial, accounting or tax advice and you should consult with external professionals for advice tailored to your situation prior to making any decisions.
