GST in Australia, India, and Canada: How the Same Word Means Three Different Things

"GST" stands for Goods and Services Tax, and it exists in Australia, India, Canada, New Zealand, Singapore, and various other countries. The acronym is consistent. The actual tax system is not. An Australian small business owner who expands into India for the first time, or a Canadian freelancer who takes on Australian clients, often discovers that "GST" in their new market behaves nothing like the GST they're used to.

This article compares the three largest GST regimes — Australia, India, and Canada — for any small business operating across them or thinking about doing so. The differences matter for invoicing, pricing, registration thresholds, and compliance.

Australia: GST as a single national VAT

Australian GST is the simplest of the three. Introduced in 2000, it's a single national tax at 10% on most goods and services.

Key parameters

• Rate: 10% (with a few exemptions for basic food, education, healthcare).
• Registration threshold: AUD 75,000 in annual turnover (AUD 150,000 for not-for-profits).
• Filing frequency: Quarterly BAS (Business Activity Statement) by default; monthly for larger businesses.
• Recovery mechanism: Input tax credits (you reclaim GST you paid on business expenses).
• Cross-border: Exports are GST-free; imports above AUD 1,000 attract GST at customs.

Invoicing requirements

For invoices over AUD 82.50 (including GST), a valid tax invoice must include the words "Tax Invoice," the seller's ABN, the date, a description of items, the GST amount, and the total. Below that threshold, simpler receipts suffice.

Practical takeaway

Australian GST is the easiest of the three to comply with. The single rate, predictable quarterly filing, and clear invoice requirements make it manageable even for solo operators.

India: GST as a federal-state hybrid

Indian GST, introduced in 2017, replaced a tangle of pre-existing taxes (VAT, service tax, excise) with what was supposed to be a unified system. It's unified compared to what came before. It is not, by international standards, simple.

Key parameters

• Rates: Multiple slabs — 0%, 5%, 12%, 18%, 28% — applied based on item classification (HSN codes for goods, SAC codes for services). Some items have additional cess on top.
• Registration threshold: ₹40 lakh for goods, ₹20 lakh for services (with state-specific variations in certain "special category" states).
• Filing frequency: Monthly returns (GSTR-1 for outward supplies, GSTR-3B for summary) plus an annual return.
• Recovery mechanism: Input tax credit (ITC) with strict matching requirements against your suppliers' filings.
• Cross-border: Exports zero-rated with refund option; imports attract IGST.

The federal-state split

The unique feature: GST in India splits into CGST (central) and SGST (state) for intra-state sales, or IGST (integrated) for inter-state sales. Same total rate (e.g., 18%), but split between governments. The invoice must reflect this split correctly — wrong split is a common error.

E-invoicing

Above ₹5 crore aggregate turnover, businesses must use the IRN (Invoice Reference Number) system — each invoice is registered with the GST portal before issuance, producing a unique IRN and QR code that must appear on the printed invoice.

Invoicing requirements

Required fields: GSTIN of supplier and recipient, HSN/SAC codes, CGST + SGST or IGST breakdown, place of supply, sequential invoice number, IRN+QR if applicable.

Practical takeaway

Indian GST is the most complex of the three. Solo and small businesses need either dedicated software or a CA to navigate it. We covered the Mumbai CA practice management story for context on what this looks like in practice.

Canada: GST + PST + HST + QST

Canadian "GST" is technically a 5% federal tax, but provincial sales taxes layer on top in most provinces, producing a regime that's deceptively named.

Key parameters by province (broadly)

• Alberta: 5% GST only.
• British Columbia: 5% GST + 7% PST = 12% total (separate filings).
• Ontario, Nova Scotia, NB, NL, PEI: Harmonized Sales Tax (HST) combining federal and provincial: 13-15% depending on province (single combined filing).
• Quebec: 5% GST + 9.975% QST = 14.975% total (separate filings to different tax authorities).
• Saskatchewan, Manitoba: 5% GST + 6-7% PST.

Registration threshold

CAD 30,000 over four consecutive calendar quarters. Once over, registration is mandatory and you must charge GST/HST going forward.

Filing frequency

Depends on revenue size — annual for very small, quarterly for medium, monthly for larger businesses.

Invoicing requirements

For invoices over CAD 30, must include supplier's name and GST/HST registration number, date, total, and amount of GST/HST (or note that it's included). Provincial sales tax handling varies by province.

The destination-based wrinkle

For services delivered to clients in other provinces, you generally charge the recipient's provincial rate. A BC-based consultant invoicing an Ontario client typically charges 13% HST, not BC's 12%.

Practical takeaway

Canadian GST is mid-complexity. The federal layer is simple; the provincial layer requires per-province awareness. HST provinces are easier than non-HST provinces.

The cross-country comparison table

What this means for cross-country businesses

If you operate across multiple GST regimes:

1. Don't assume your home country's GST behaves anywhere else

An Australian seller registering for Indian GST encounters a different beast entirely. Don't assume "I've done GST before" prepares you.

2. Per-country invoice templates

Each country's GST regime requires its own invoice format. You can't use the same template across all three.

3. Per-country registration thresholds

Crossing thresholds in each country triggers registration obligations independently. Track them separately.

4. Local tax advisors per country

Don't assume your Australian accountant can advise on Indian GST. Each regime requires local expertise.

5. Software with multi-regime support

Your invoicing system must handle all the GST formats you need. Some systems support one regime well and others poorly. Test before committing.

New Zealand, Singapore, and others

For completeness:

• New Zealand: 15% single rate, similar to Australian structure.
• Singapore: 9% as of 2024, single national rate.
• Malaysia: Reverted to SST (Sales and Service Tax) in 2018 after a brief GST experiment.

The pattern: "GST" outside India is generally simpler than Indian GST and generally similar to a national VAT.

The wider lesson

"GST" is a useful shorthand. It is not a system. Each country's implementation differs in rate structure, threshold, filing frequency, cross-border handling, and invoicing requirements. A small business operating across multiple GST jurisdictions needs to treat each one as its own tax system with its own learning curve.

The good news: each individual regime is manageable once set up properly. The bad news: there is no "GST setup" that works everywhere. You set up per country.

If you operate across two or more, the time investment in getting each one right is worth it. If you operate in just one, learn it deeply and don't assume your knowledge transfers.