GST Guide for Business

How GST works in one paragraph

GST is a broad-based tax on most goods and services sold in Australia. Registered businesses add it to their prices, collect it from customers, and claim back the GST included in their own business purchases. The difference — GST collected minus GST credits — is what you remit to (or receive from) the ATO through your Business Activity Statement. You're not really paying GST as a business; you're collecting it on the government's behalf. Treating collected GST as your own money is the single most common way GST hurts small businesses.

This is general information — the ATO's guidance and your BAS or tax agent are the reference points for your own situation.

Who has to register

Registration is compulsory once your GST turnover meets the registration threshold the ATO sets (a separate, different threshold applies to taxi and ride-sourcing drivers, for whom registration is required from the first dollar). Below the threshold, registration is optional.

Voluntary registration is worth considering if your customers are mostly businesses (they can claim the GST back, so your effective price doesn't rise) or if you have significant GST-bearing costs to claim credits on. It's less attractive if you sell to consumers and your competitors are unregistered. Once registered, you take on the full invoicing and BAS routine, so weigh the admin against the benefit.

Not everything has GST on it

Three categories matter in practice:

• Taxable sales — the default: you charge GST and can claim credits on related purchases.
• GST-free sales — no GST charged, but you can still claim credits. Common examples include most basic food, many health and education services, and exports.
• Input-taxed sales — no GST charged, and no credits on related purchases. Residential rent and most financial supplies sit here.

If your business straddles categories — a café selling both basic food items and prepared meals, say — getting your point-of-sale and accounting codes right matters more than any other GST task, because every misclassified sale compounds in the BAS.

Tax invoices and credits

You can generally only claim a GST credit if you hold a valid tax invoice (for purchases above the ATO's small-amount threshold). A valid tax invoice must identify the seller and their ABN, the date, a description of what was supplied, and the GST — with extra requirements for larger invoices. Two habits protect your credits:

• Capture the document at the time of purchase — a receipt-capture app feeding your accounting system beats a shoebox in every way that counts.
• Watch for suppliers who aren't registered — an invoice with no GST on it gives you no credit to claim, and an ABN that doesn't check out can trigger withholding obligations. The ABN Lookup register makes verification trivial.

The BAS rhythm

Most small businesses report quarterly; larger ones monthly, and some very small ones annually — the ATO sets the cycles and the due dates for each. The BAS brings together GST, PAYG withholding on wages, and PAYG instalments in one lodgement. Two choices shape how it feels:

• Cash vs accruals accounting for GST. On a cash basis you account for GST when money actually moves — usually kinder to SME cash flow. Eligibility rules apply.
• Setting the money aside. A separate bank account receiving a slice of every week's takings turns the BAS from a crisis into a transfer. What slice? Your accountant can tell you from your actual mix of sales and costs.

Common traps

• Claiming credits on input-taxed or private-use purchases, or on the private portion of mixed-use items.
• Forgetting GST applies to some unusual transactions — business asset sales, barter arrangements, some insurance settlements.
• Letting bookkeeping lag so the BAS is built from guesswork; late and amended BAS lodgements invite attention and penalties.

GST is one of several obligations that reward a steady back-office rhythm rather than heroic quarterly efforts — the finance function page covers how the pieces fit, and the modern SME back office shows what good looks like end to end.