Starting a business often raises the same question: do I need to register for GST now, or can I wait? The answer matters because registration affects your pricing, invoicing, BAS reporting, cash flow and ability to claim GST credits on eligible business expenses.

GST registration is not simply an administrative box to tick. Registering too late can create unexpected liabilities, while registering voluntarily without a clear plan can add compliance work that may not suit a very small or early-stage business. This guide explains the key rules and practical steps for Australian sole traders, companies, partnerships and trusts.

GST registration starts with the nature of your sales

Goods and services tax, commonly called GST, applies to many sales made in the course of carrying on an enterprise in Australia. The GST payable on a taxable supply is generally 10% of its value.

For a sale to be taxable, it generally needs to be made:

  • for payment or other consideration

  • in the course of carrying on an enterprise

  • connected with Australia

  • by an entity that is registered, or required to be registered, for GST.

Not every sale is taxable. Australian GST law distinguishes between taxable supplies, GST-free supplies and input-taxed supplies.

A taxable supply is the usual category for many businesses, such as a consultant providing services, a retailer selling products, or a tradesperson completing work for a customer.

GST-free supplies do not have GST added to the sale price, but a registered business may still be able to claim GST credits for eligible purchases relating to those supplies. Certain food, health, education and export-related supplies can fall into this category, although the treatment depends on the precise legal requirements.

Input-taxed supplies also do not have GST added to the sale price. However, GST credits are generally not available for purchases that relate to making input-taxed supplies. Residential rent and many financial supplies are common examples.

This distinction is important before registration because a business should not assume that every dollar of income is treated in the same way for GST purposes.

When GST registration is compulsory

A business or enterprise generally must register for GST when its GST turnover reaches the registration threshold.

The current threshold is:

  • $75,000 or more for most businesses and enterprises

  • $150,000 or more for non-profit organisations.

These figures refer to GST turnover, not profit. A business can have modest profits, or even make a loss, while still needing to register because its sales have reached the relevant turnover threshold.

GST registration is also required in some circumstances regardless of turnover. This includes providing taxi or limousine travel for passengers, including ride-sourcing services. A business may also need GST registration to claim fuel tax credits.

Once an entity is required to register, it must apply for GST registration within 21 days. Waiting until the end of the financial year, or until the accountant prepares the tax return, can be risky. GST obligations are determined by the date the business became required to register, not simply by the date the business completes its registration application.

A late registration can create a difficult commercial issue. If a business has quoted customers a GST-inclusive price but was not registered when it should have been, it may still face a GST liability without being able to recover an additional amount from those customers.

How to calculate your GST turnover

GST turnover is not simply the figure shown as sales in a profit and loss statement. It is based on the value of supplies made in the course of the enterprise, subject to specific exclusions.

When considering the registration threshold, the key tests are generally:

  • Current GST turnover, which looks at the current month and the previous 11 months.

  • Projected GST turnover, which looks at the current month and the following 11 months.

A business may need to register if either test reaches the relevant threshold. However, there is an important qualification. If current turnover has reached the threshold but projected turnover is below it, registration may not be required.

In working out GST turnover, certain amounts are excluded. These commonly include:

  • GST included in the price of sales

  • input-taxed sales

  • sales that are not connected with the enterprise

  • sales not connected with Australia

  • certain supplies to associates that are not for payment and are not taxable.

When calculating projected turnover, a business generally does not include proceeds from selling a capital asset, such as a business vehicle or equipment. It also generally excludes sales made solely because the business is ceasing or substantially and permanently reducing its size or scale.

A practical scenario

Consider a sole trader who provides digital marketing services. Their work has grown steadily after securing several ongoing client contracts. Their profits are still uncertain because they have invested in software, subcontractors and advertising, but their expected sales over the next 12 months are likely to exceed the GST registration threshold.

Because the test is based on turnover rather than profit, the sole trader may need to register even though their business has not yet produced a strong net profit. They should review the expected start date for registration, update their proposals and invoices, and make sure their accounting system separates GST correctly from that date.

Regular turnover monitoring is particularly important for seasonal businesses, consultants who win a large contract, online sellers, construction businesses and service providers whose income can rise quickly.

How to register and whether voluntary registration makes sense

Before registering for GST, a business needs an Australian business number, commonly called an ABN. GST registration can usually be added when applying for an ABN or later through the appropriate government online services. A registered tax agent or BAS agent can also assist.

Registration is linked to the entity carrying on the enterprise. This means the correct entity must register. For example, a sole trader, company, partnership and trustee of a trust are not interchangeable simply because they are connected to the same people or business activities.

Businesses below the registration threshold can generally choose to register voluntarily if they are carrying on an enterprise, or intend to do so. Voluntary registration may be useful where a business:

  • has significant start-up purchases with GST included

  • mainly deals with GST-registered business customers

  • wants its invoicing and pricing systems established before growth occurs

  • expects to exceed the threshold soon

  • needs GST registration to access fuel tax credits.

However, voluntary registration should be a considered decision. Once registered, the entity must charge GST on taxable sales, lodge activity statements and maintain GST records. A voluntarily registered business will generally need to remain registered for at least 12 months unless it was not required to be registered before cancellation.

For businesses selling mainly to consumers, registration can affect pricing. If prices cannot be increased, the GST component may need to come out of the existing sale price. For businesses selling mainly to GST-registered businesses, GST may be less of a commercial issue because eligible customers can generally claim input tax credits.

What changes once your business is registered

GST registration changes both how you charge customers and how you account for business purchases.

For taxable sales, a registered business needs to account for GST. If a price is expressed as GST-inclusive, the GST component is generally one-eleventh of the total price. For example, where a taxable sale is priced at $110 including GST, the GST component is $10 and the GST-exclusive value is $100.

A registered business should clearly consider whether quoted prices are:

  • GST-inclusive

  • GST-exclusive

  • subject to GST depending on the final nature of the supply.

Clear wording in quotes, contracts, online checkout pages and invoices helps prevent disputes. This is especially important where customers are consumers, where prices are advertised publicly, or where a business makes a mix of taxable and GST-free supplies.

Registration may also allow the business to claim input tax credits for eligible purchases. Broadly, an acquisition needs to be connected with carrying on the enterprise, supplied to the business as a taxable supply, and supported by appropriate records.

Common examples of purchases that may include claimable GST, depending on the circumstances, include:

  • stock and trading supplies

  • software subscriptions and business technology

  • advertising and marketing

  • professional fees

  • commercial rent and office costs

  • tools, equipment and business assets

  • certain vehicle and travel costs.

The purchase must genuinely relate to the business. A private expense cannot be converted into a business GST claim simply because the business is registered.

Where an expense has both business and private use, the GST credit usually needs to be apportioned. This often arises with mobile phones, internet, motor vehicles, home office expenses and assets shared between business and personal use.

Care is also needed with purchases relating to input-taxed activities, as GST credits may be limited or unavailable. Property transactions, financial services, mixed-use assets and cross-border transactions can require more detailed advice.

BAS reporting, tax invoices and record keeping

After registration, GST is reported through the business activity statement, commonly known as the BAS. The BAS may also include other obligations, such as PAYG withholding, PAYG instalments or other taxes, depending on the business.

The basic GST calculation is straightforward in principle:

  • GST collected on taxable sales

  • less GST credits claimed on eligible business purchases

  • equals the net GST amount payable, or refundable, for the reporting period.

In practice, errors often arise because sales are coded incorrectly, expenses are claimed without supporting documents, GST-free income is treated as taxable, or private purchases are included in business accounts.

A registered business may report GST quarterly or monthly, depending on its circumstances and applicable rules. Some businesses can also be eligible to account for GST on a cash basis, while others account on a non-cash basis.

Cash accounting generally recognises GST when money is received from customers and paid to suppliers. Non-cash accounting generally recognises GST by reference to invoices and other attribution rules, rather than waiting for payment. The best approach depends on eligibility, cash flow, accounting systems and the nature of the business.

Tax invoices are a key part of GST compliance. If a customer is registered for GST and wants to claim a GST credit, they may need a valid tax invoice from the supplier. For higher-value taxable purchases, the recipient generally needs a tax invoice to support its input tax credit claim.

A business should maintain orderly records of:

  • sales invoices and point-of-sale records

  • supplier invoices and receipts

  • bank statements and payment records

  • credit notes and adjustment notes

  • contracts and quotes

  • business asset purchases and sales

  • calculations supporting GST apportionment or adjustments

  • BAS lodgments and working papers.

GST records generally need to be kept for at least five years. Good accounting software can make this easier, but software does not remove the need to review how transactions have been coded.

Cancelling GST registration and staying on top of change

GST registration should be reviewed when a business is sold, closed, restructured or materially reduced in size. If an entity stops carrying on an enterprise, it must apply to cancel its GST registration within 21 days.

A business may also be able to cancel registration if its turnover falls below the compulsory registration threshold and it is no longer required to remain registered. This should not be treated as an automatic decision. Cancellation can affect GST credits, final BAS obligations and the GST treatment of assets still held by the business.

The final BAS may require adjustments for trading stock, equipment, vehicles or other assets retained for private use after cancellation. Selling a business, changing from a sole trader to a company, or transferring assets into a trust can also have GST consequences that should be considered before documents are signed or transactions are completed.

The key takeaway is that GST registration is not just about crossing a sales figure. It is about understanding the correct entity, monitoring turnover, applying the right GST treatment to sales and purchases, and keeping records that support the BAS.

This article is general information only and is not personal financial or tax advice. GST outcomes can depend on the facts, including the business structure, type of supplies, contracts and timing. Speak with a registered tax agent or accountant, such as, about advice tailored to your circumstances.