What to Include on an Invoice (Complete Checklist)

A well-built invoice does more than ask for money — it sets expectations, looks professional, and removes every reason a client might have to delay payment. Yet a surprising number of invoices are missing details that cause confusion, back-and-forth emails, or late payments. This checklist covers exactly what a professional invoice should include, and why each item matters.

1. The word “Invoice”

It sounds obvious, but clearly labelling the document Invoice matters. It distinguishes the document from a quote, an estimate, or a receipt, and helps your client’s accounts team route it correctly. If you send quotes and invoices that look identical, expect delays.

2. A unique invoice number

Every invoice needs its own unique, sequential number (for example INV-0001, INV-0002). This is not just good practice — in most countries it is a legal requirement for tax records. A consistent numbering system also makes it far easier to track which invoices have been paid and which are outstanding.

3. Your business details

Include your business name, address, email, and phone number. If you operate as a registered company or are registered for sales tax, VAT or GST, include your registration or tax identification number too. This is what makes the invoice official and gives your client confidence they’re dealing with a real business.

4. Your client’s details

Add the client’s name, company, and billing address. For larger companies, ask for a contact name or a purchase order (PO) number — invoices addressed to “Accounts Payable” with a matching PO number tend to get paid much faster because they slot straight into the client’s approval process.

5. Invoice date and due date

State the issue date and, critically, the due date. “Due on receipt” or “Net 30” means little if you don’t spell out the actual calendar date. A clear due date is the single most effective way to encourage on-time payment.

6. An itemised list of products or services

This is the heart of the invoice. For each line item include:

A short, clear description of the product or service
The quantity or hours
The unit price or rate
The line total

Vague descriptions like “Consulting” invite questions. “Website homepage design — 12 hours @ $75” is clear and hard to dispute.

7. Subtotal, tax, discounts and the grand total

Show the maths so there is nothing to argue about:

Subtotal (the sum of all line items)
Any discount applied
Tax (VAT, GST or sales tax) with the rate shown
The grand total due, in your chosen currency

Always make the final amount due the most prominent number on the page.

8. Payment terms and methods

Tell the client exactly how and when to pay. Include your accepted payment methods (bank transfer, card, PayPal, etc.), the relevant account details, and your payment terms (for example “Payment due within 30 days”). If you charge late fees, state the policy here.

9. Notes or a thank-you

A short note — “Thank you for your business!” or delivery instructions — adds a professional, friendly touch and is a good place for any project-specific terms.

A faster way to build all of this

You don’t need to assemble these elements by hand every time. Our free invoice generator includes every item on this checklist, calculates your subtotals and tax automatically, lets you add your logo, and exports a clean PDF — all in your browser, with nothing stored on a server.

Quick checklist

Get these nine things right and you’ll look professional, avoid disputes, and — most importantly — get paid on time.