How to write an invoice

Updated 5 November 2026

To write an invoice, put the word “Invoice” and a unique number at the top, then the invoice date and due date, your details and your client’s details, a line for each product or service with its quantity, price and amount, any tax and discount, the total due, and how to pay. Send it as a PDF.

What goes on an invoice?

Every invoice needs the same core details, in roughly this order:

1. The word “Invoice” (or “Tax Invoice” where your tax rules require it) and a unique invoice number.
2. Invoice date and due date, or payment terms such as “Net 30”.
3. Your details: business name, address, email or phone, and your tax number if you are registered (GSTIN, VAT number, ABN, EIN and so on).
4. Your client’s details: name and billing address, plus their tax number for business-to-business sales where required.
5. Line items: a description of each product or service, the quantity, the unit price and the line amount.
6. Subtotal, discounts, tax and the total. Show each tax separately with its rate.
7. Payment details: bank account, UPI ID, PayPal or a payment link.
8. Optional notes and terms, such as a thank-you, late-payment terms or a reference number.

Invoice example

Description	Qty	Rate	Amount
Logo design	1	$800.00	$800.00
Brand guidelines (hours)	6	$75.00	$450.00
Subtotal			$1,250.00
Sales tax (8%)			$100.00
Total due			$1,350.00

How do I number invoices?

Use a sequence with no gaps or repeats, such as INV-0001, INV-0002. Many businesses add the year (2026-041) so numbering restarts cleanly each year. Some countries, such as India, cap the length (16 characters) and require a new series each financial year. Never reuse a number, even for a cancelled invoice. Issue a credit note instead.

What payment terms should I use?

“Due on receipt”, Net 7, Net 14 and Net 30 are the most common. Shorter terms get you paid sooner. State the exact due date as well, because “Net 30” is easy to misread. See the payment terms guide for what each term means.

How do I send an invoice?

Send a PDF. It looks the same on every device and can’t be edited by accident. On a phone, the invoice generator can share the PDF straight to WhatsApp, email or any other app. Keep a copy of every invoice you send for your accounts and tax return.

Make one now: the free invoice generator creates a PDF invoice in your browser, with no sign-up.