Creating Subcontractor Invoices: Essential Guide For Australian Businesses

Stepping into subcontracting gives you flexibility and access to specialist skills - but it also means getting your paperwork right from day one.

For subcontractors and the businesses that engage them, invoices aren’t just about getting paid. They’re a core part of staying compliant with Australian tax rules, keeping cash flow healthy, and building trust with clients.

If you’re new to subcontracting (or you’ve just started engaging subcontractors), this guide explains what a compliant subcontractor invoice should include, how GST and ABN rules work, and the legal documents that support smooth invoicing and payment.

Read on for a practical, plain-English overview - and how we can help you build a simple, compliant invoicing process that supports your business as it grows.

What Is A Subcontractor Invoice?

A subcontractor invoice is a payment request issued by a subcontractor (a business engaged to perform part of a larger project) to the contractor or client who engaged them.

Unlike employees, subcontractors don’t receive wages or salary. You bill for your work based on agreed rates, hours, milestones, or deliverables. The invoice documents exactly what was done, when, and how much is payable - forming an essential record for both payment and tax.

In Australia, invoices must meet certain content standards to be valid for accounting and tax purposes. Clear, complete invoices also reduce the risk of disputes and make it easier to follow up if payment is late.

What Must A Subcontractor Invoice Include In Australia?

To be accepted by clients (and compliant with ATO requirements), include the following on every invoice:

• Your business details and ABN: Your legal name or business name, address, and Australian Business Number (ABN). If you don’t provide an ABN, your payer may be required to withhold 47% from the payment under no-ABN withholding rules.
• Client details: The client’s name and address. For tax invoices of $1,000 or more, you must include the recipient’s identity or ABN on the invoice.
• Invoice date: The date you issued the invoice.
• Unique invoice number: A sequential or otherwise unique invoice number for tracking.
• Clear description of the services: Be specific about the work performed, the date range, milestones completed, and any units (hours, days, or quantities). Specificity helps prevent disputes.
• Amounts payable: Line items (if applicable), subtotals, any discounts, and the total amount due.
• GST information (if registered): If you’re registered for GST and the sale is taxable, show the words “Tax Invoice”, state your ABN, and either:
  • Show the total price including GST and the amount of GST, or
  • State that the total includes GST (if it’s clear which items are taxable).

  Do not charge GST or label your document a tax invoice if you’re not registered for GST.

• Payment terms and methods: For example, “14 days from invoice date”, plus your bank details, BPAY, or PayID.
• Contact details: Include a contact name, phone and/or email for any invoice queries.

Tip: If you regularly bill multiple clients, set up a reusable template so you don’t miss essentials. It also helps to verify client details (including the ABN where relevant) before issuing invoices - a quick check against the ABR can save time later, and many businesses use a simple process for checking if an ABN is active.

Step-By-Step: How To Create And Manage Subcontractor Invoices

1) Get Your Business Details In Order

Before you invoice, make sure your business setup is clear on the invoice itself.

• Choose a structure: Sole trader, partnership, or company. Many subcontractors start as sole traders; as you scale or manage higher risk, a company can offer limited liability and a more professional profile.
• Apply for an ABN: You’ll need your ABN on your invoices. Without an ABN, payers may need to withhold tax from your payment.
• Decide on GST: If your actual or projected GST turnover is $75,000 or more in a 12‑month period, you must register and include GST on taxable sales.

2) Put A Written Contract In Place

Before issuing your first invoice, have a written agreement that sets out scope, rates, milestones, and payment terms. A tailored Subcontractor Agreement is the best way to reduce grey areas and ensure your invoicing aligns with what was agreed.

Where you sell services or goods on repeat or to different clients, it can help to standardise your position using Terms of Trade that clearly explain invoicing, due dates, late fees, and consequences of non-payment.

3) Use A Compliant Template (Or Accounting Software)

Set up a template that always includes the required fields above. Most accounting tools (e.g. Xero, MYOB, QuickBooks) support Australian tax invoices, but it’s your responsibility to make sure the template actually matches what the ATO requires.

If you work to milestones or progress claims, adapt your template to show the stage, percentage complete, and balance remaining. Consistency builds confidence and speeds up approvals.

4) State Clear Payment Terms And Methods

Spell out how and when you expect to be paid. This helps your clients plan and gives you a firm basis to follow up. Simple, standard wording is fine - for example, “Payment due 14 days from invoice date by EFT or PayID”.

If you intend to add fees or interest for overdue amounts, ensure your written agreement supports it and that your fee approach is lawful. See our practical overview on setting invoice payment terms and how late payment fees work under Australian law.

5) Send Promptly And Keep Records

Invoice immediately when work is complete or when a contract milestone is reached. Keep a copy of every invoice you issue and receive - businesses must keep financial records for at least five years.

Use polite, timely reminders as the due date approaches and passes. A short follow-up process (for example, day 1 reminder, day 7 escalation) makes a big difference to cash flow.

6) Consider Workflow Options Like RCTIs

In some industries, clients issue “recipient created tax invoices” (RCTIs) on your behalf. This can streamline billing for regular or variable work. RCTIs require a written agreement and specific GST wording and process controls, which we explain in detail in our guide to RCTIs.

GST, ABNs And “Tax Invoice” Rules: What Do You Need To Know?

When Do You Register For GST?

If your actual or projected GST turnover is $75,000 or more in a 12‑month period, you must register for GST. Once registered, you generally charge 10% GST on taxable supplies and lodge Business Activity Statements (BAS).

When Can You Call It A “Tax Invoice”?

Only issue a tax invoice if you’re registered for GST and the sale is taxable.

• For tax invoices under $1,000, include your identity, ABN, invoice date, a clear description, the price, and the GST amount (or a statement that GST is included).
• For tax invoices of $1,000 or more, you must also include the recipient’s identity or ABN.

If you’re not registered for GST, don’t add GST and don’t label the invoice as a tax invoice. You can simply issue an invoice (not a tax invoice).

What If The Supplier Has No ABN?

Where a supplier doesn’t quote an ABN and no exemption applies, the payer may need to withhold 47% from the payment and send that amount to the ATO (no‑ABN withholding). This rule often surprises new subcontractors and can significantly impact cash flow, so it’s important to include your ABN on invoices.

How Do GST Credits And Timing Work?

Your clients generally need valid tax invoices to claim GST credits. If a client asks, you must provide a valid tax invoice within 28 days. It’s good practice to issue compliant invoices at the start to avoid rework or delayed payment.

A Quick Word On Tax Advice

This is general information only - it’s not financial or tax advice. Your situation may be different (for example, if you make mixed or input‑taxed supplies, or you’re on cash vs accruals). It’s sensible to speak with your accountant or tax adviser if you’re unsure about your GST or BAS position.

Legal And Contract Essentials Around Invoicing

Getting paid on time isn’t just about the invoice; it’s also about the contract behind it and the policies around your business. Here are the main legal touchpoints to consider.

Contract Terms That Support Smooth Invoicing

• Scope, rates and milestones: Your agreement should clearly set out what you’ll do, how much you’ll charge, and when you can invoice (e.g. on completion, progress claims, or monthly).
• Approval process: If the client needs to sign off on deliverables or timesheets before you invoice, outline who does this and when.
• Payment terms and consequences: Spell out due dates, any late fees (if permitted), suspension rights for non‑payment, and steps for dispute resolution.
• Variations: Include how changes in scope are agreed, priced and invoiced.

These fundamentals are usually captured in a tailored Subcontractor Agreement for project‑based engagements, or in your standing Terms of Trade for repeat work.

Australian Consumer Law (ACL) And Small Business Contracts

If you deal with consumers, the ACL applies to your representations, warranties and refund rights. Even in B2B settings, the unfair contract terms regime can apply to standard‑form contracts with small businesses (generally, businesses with fewer than 100 employees or under $10 million turnover). Make sure your payment and invoicing terms are clear, fair, and not one‑sided.

Privacy And Data

The Privacy Act primarily applies to “APP entities” - including businesses with an annual turnover of more than $3 million, and some small businesses in specific circumstances (for example, health service providers, those trading in personal information, or contractors to the Commonwealth). Even if you’re under the threshold, it’s best practice to be transparent about how you collect and use client details.

If you collect personal information online (names, emails, addresses or payment details), consider having a clear, accessible Privacy Policy. If you operate a website or portal where clients log in to view invoices, Website Terms and Conditions can help set expectations and limit your liability.

Recordkeeping

Australian businesses must keep sufficient financial records - including invoices - for at least five years. Good records support your BAS, income tax returns, and any disputes that might arise.

Practical Tip: Align Your Contract And Your Invoice

Your invoice should mirror your contract. If your agreement says “30% deposit on signing and 70% on completion,” make sure your invoices track those milestones and use the same language. Consistency makes approvals faster and reduces queries.

Common Mistakes To Avoid

• Missing ABN or key details: Leaving off your ABN, an invoice number, or a clear description can delay payment and create compliance issues.
• Charging GST when you’re not registered: Only add GST (and issue a tax invoice) if you’re registered. If you’re not registered, don’t label your document a tax invoice.
• Vague descriptions: “Consulting services” is too broad. Be specific about what you delivered and when.
• Inconsistent terms: If your invoice says “7 day terms” but your contract says “30 days”, expect confusion. Keep your documents consistent.
• No written agreement: Invoicing without a contract increases the risk of disputes - especially around what’s included and when payment is due.
• Late invoicing and follow‑ups: Delays in sending invoices (and reminders) can push payments out by weeks or months.
• Ignoring RCTI rules: If you use recipient created tax invoices, ensure your agreement and processes satisfy the ATO’s requirements.

Optional: Add A Short, Friendly Collections Process

Many small businesses find a simple three‑step reminder flow highly effective: a polite reminder a few days before due date, a second reminder the day after due, then a firmer escalation at seven days overdue. If your contract allows for late fees or suspension of services, apply these consistently and fairly, and ensure they’re legally compliant (see our guidance on late payment fees).

Protecting Confidentiality

When you share scopes, pricing sheets, or unique processes to support your invoice or progress claims, consider using a Non‑Disclosure Agreement (NDA). It’s a simple way to preserve confidentiality around sensitive commercial information.

Key Takeaways

• A clear, complete subcontractor invoice supports prompt payment, tax compliance and professional client relationships.
• Include your ABN, client details, invoice date and number, an accurate description of services, totals, payment terms, and GST details if you’re registered.
• Only issue a “Tax Invoice” if you’re registered for GST; if your invoice is $1,000 or more, include the recipient’s identity or ABN.
• Without an ABN, payers may need to withhold 47% under no‑ABN withholding rules, so make sure your ABN is on every invoice.
• Back up your invoices with solid contracts - a tailored Subcontractor Agreement or clear Terms of Trade will make invoicing and follow‑up easier.
• Consider workflow options like RCTIs where appropriate, and ensure your processes meet ATO requirements.
• If you collect personal information online, support your invoicing workflow with a transparent Privacy Policy and appropriate website terms.

If you’d like a consultation on setting up or reviewing your subcontractor invoices, contracts and payment terms, you can reach us at 1800 730 617 or team@sprintlaw.com.au for a free, no‑obligations chat.