GST for Tradies: A Simple Guide to Tax on Quotes and Invoices

Do you need to charge GST?

The rule is straightforward: if your trade business turns over more than $75,000 per year (or you reasonably expect to), you must register for GST. Once registered, you charge 10% GST on your services and materials, and you can claim GST credits on your business purchases.

If you're under $75,000 turnover, registration is optional — but many tradies register anyway because it lets them claim GST credits on tools, materials, and vehicle expenses.

GST on quotes

Every quote you send should clearly show the GST component. There are two ways to present it:

Tax-exclusive (recommended for trade quotes):

• Subtotal: $4,440.00
• GST (10%): $444.00
• Total: $4,884.00

Tax-inclusive:

• Total (inc. GST): $4,884.00

Tax-exclusive is the standard in the trade industry because it makes it clear what the client is paying for work versus tax. Most accounting software and quoting tools default to this format.

Line item pricing

You can set line item prices as either tax-exclusive or tax-inclusive, as long as your totals are consistent. The important thing is that the final quote clearly shows the GST amount.

For example, if you're quoting a switchboard upgrade:

• Switchboard supply & install: $2,400.00
• Cable & conduit (45m @ $18.89/m): $850.00
• Safety switches × 4: $620.00
• Labour (6h @ $95/h): $570.00
• Subtotal: $4,440.00
• GST (10%): $444.00
• Total: $4,884.00

GST on invoices

Your tax invoices must include:

1. The words "Tax Invoice"
2. Your business name and ABN
3. The date of issue
4. A description of what was supplied
5. The GST amount (or a statement that the total includes GST)
6. The total amount

For invoices under $1,000, you can use a simplified format. For invoices over $1,000, you need the full format including the buyer's name and address.

Common mistakes

Not separating materials and labour — Some tradies quote a single lump sum. This is fine legally, but breaking it down helps if the client queries the price and makes your quotes look more professional.

Forgetting GST on variations — If you agree to extra work during a project, the variation quote needs GST too. Don't just add the net amount.

Mixing up GST-free and taxable supplies — Most trade work is taxable (10% GST). But some things are GST-free, like certain types of insurance or government grants. When in doubt, check with your accountant.

Late BAS lodgement — If you're on quarterly BAS, the deadlines are 28 October, 28 February, 28 April, and 28 July. Late lodgement attracts penalties.

How 33 Trade handles GST

33 Trade has GST built into every quote and invoice. When you add line items, GST is calculated automatically at 10%. You can set items as taxable or tax-free, and the totals update in real time.

When you sync with Xero, the GST components flow through correctly — so your BAS reporting is accurate without manual reconciliation.