Invoice
What an invoice is, what to include, NZ GST and tax invoice rules, and how to get paid on time.
Published Thursday 23 July 2026
Table of contents
Key takeaways
- An invoice is a document that charges a customer for goods or services you've provided, and it's often called a bill.
- If you're GST-registered in New Zealand, your invoice is usually a tax invoice that shows your GST number and the GST amount.
- A clear invoice records the sale, supports your GST and tax obligations, and helps you get paid on time.
- Sending invoices promptly with clear payment terms protects your cash flow.
What is an invoice?
An invoice is a document that charges a customer for goods or services you've provided. It's also called a bill.
In New Zealand, an invoice from a GST-registered seller is commonly called a tax invoice, because it shows the GST charged on the sale.
What an invoice is used for
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Disclaimer
This glossary is for small business owners. The definitions are written with their requirements in mind. More detailed definitions can be found in accounting textbooks or from an accounting professional. Xero does not provide accounting, tax, business or legal advice.
An invoice does more than ask for money. It's a working record that keeps your business organised and your obligations covered.
Here's what you use an invoice for:
- Request payment for goods or services you've supplied
- Keep accurate financial records for your business
- Support your GST and tax compliance
- Track cash flow and any money owed to you as accounts receivable
- Provide proof that a transaction took place
What to include on an invoice
A complete invoice leaves no room for confusion and makes it easy for your customer to pay. Include these details on every invoice you send:
- The word "invoice" or "tax invoice"
- A unique invoice number
- Your business name, address and GST number
- The customer's name and contact details
- The invoice date
- The due date
- An itemised description with quantities and unit prices
- The subtotal before GST
- The GST amount, charged at 15%
- The total amount payable
- Your payment terms and accepted payment methods
Invoice vs bill, receipt and quote
These 4 documents are easy to mix up, but each has a distinct job. Knowing the difference keeps your records clean.
- An invoice and a bill are usually the same document. It's an invoice when you send it, and a bill when your customer receives it.
- A receipt is proof that payment has already been made. You issue it after the money arrives.
- A quote is an estimate you give before any work starts, so the customer knows the likely cost.
Types of invoices
You'll come across several invoice types as your business grows. Here's a quick guide to the most common ones:
- Standard or sales invoice: charges a customer for a completed sale
- Purchase invoice: a bill you receive from a supplier
- Recurring invoice: sent on a repeating schedule for ongoing work
- Interim invoice: bills part of a larger project as it progresses
- Credit note: reduces or reverses an amount already invoiced
- Overdue invoice: an invoice that's passed its due date unpaid
- Tax invoice: shows the GST charged on a sale
GST and tax invoices in New Zealand
If you're registered for GST in New Zealand, you generally need to give customers information about the GST on their purchase. The standard GST rate is 15%.
Since April 2023, the rules ask you to provide taxable supply information rather than a formally titled "tax invoice". In practice, a clear invoice showing your GST number and the GST amount usually covers what's needed. For the details that apply to your situation, check with Inland Revenue or your accountant.
When to send an invoice
The right moment to invoice depends on how you work and what you've agreed with your customer. Common timings include:
- When you complete the work or deliver the goods
- At the point of sale
- On a recurring schedule for ongoing services
- At agreed project milestones
- As an upfront deposit before work begins
Whichever timing you choose, send the invoice promptly. The sooner it goes out, the sooner you're paid, and the healthier your cash flow stays.
Payment terms and getting paid on time
Payment terms tell your customer when payment is due. Common terms are Net 7, Net 14 and Net 30, meaning payment is due within 7, 14 or 30 days of the invoice date.
You can also offer an early-payment discount to reward fast payers, or set a late fee to discourage overdue accounts. Clear terms paired with prompt invoicing tend to speed up payment. For more ideas, see these invoice payment terms tips.
Late payment is a real cost for Kiwi businesses. According to Xero Small Business Insights, the cost of late payments to Kiwi small businesses rose 81% to $827 million in 2023.
How to create and send an invoice
You can create an invoice from a manual template, such as a spreadsheet or word processor, or use invoicing software that fills in the details for you. Either way, give each invoice a unique, sequential number so your records stay in order. For a step-by-step walkthrough, read this guide on how to invoice.
In New Zealand, you can also send e-invoices through the Peppol network, which exchanges invoices directly between accounting systems for faster, automated processing. Xero's online invoicing software lets you create, send and track invoices in one place.
Simplify your invoicing with Xero
Clear, consistent invoices help you keep records tidy, stay on top of GST, and get paid on time. When invoicing is quick and reliable, you spend less time chasing payments and more time running your business. See how Xero can help you create, send and track invoices, and get one month free.
FAQs on invoicing
Here are answers to some frequently asked questions about invoicing in New Zealand.
What's the difference between an invoice and a receipt?
An invoice requests payment for goods or services before it's paid. A receipt confirms that payment has already been received.
Does an invoice have to include GST?
You only charge GST if you're GST-registered, and then it's added at 15%. If you're not registered, your invoice won't show any GST.
When should I send an invoice?
Send it as soon as the work is done or the goods are delivered, unless you've agreed on deposits or milestones. Prompt invoicing helps you get paid sooner.
Is an invoice a legal document?
An invoice becomes a binding record of a sale once your customer accepts the goods or services. Keep copies to support your tax records and resolve any disputes.
What is a tax invoice in New Zealand?
A tax invoice is an invoice from a GST-registered seller that shows the GST charged. Since April 2023, this sits under the wider rules for providing taxable supply information.