What to Include on an Invoice (Required vs Optional)

An invoice is a request for payment, and in most countries it is also a tax record. What you must include depends on where you operate and whether you are registered for tax, so treat this page as a checklist to compare with your tax authority’s guidance, not as legal advice.

Usually required

• A unique invoice number. It identifies the invoice in your records and your client’s. Many tax authorities expect numbers to be sequential.
• The invoice date. Some countries also ask for the date of supply if it differs.
• Your name or business name and address. Use the legal name you trade under.
• Your client’s name and address. For business clients, the company name rather than a person’s.
• A description of what you supplied. Clear enough that someone else could understand what was bought.
• Quantities, prices and the total. Show the amount before tax, the tax, and the total payable.
• Your tax registration number, if you are registered. And the rate and amount of tax charged.

Optional but useful

• A due date or payment terms. For example “due 30 June” or “net 30”.
• How to pay you. Bank details, a payment link, or both.
• A purchase order number. Large clients often will not pay without it.
• A project name or reference. It helps the client match the invoice to the work.
• Notes. A short thank-you, late-payment terms you agreed in advance, or a reminder of what a deposit covered.

Things that vary by country

Some countries require specific wording such as “Tax invoice”, a tax number for the buyer, a sequential series without gaps, or invoices issued through an approved electronic system. If you invoice across borders, the rules of your own country usually apply to you, but your client may ask for extra details to satisfy theirs.

The invoice generator lets you add a tax number, a tax name and a rate per line.

A quick check before you send

1. Is the number unique and in order?
2. Are your details and your client’s details correct?
3. Does each line say what was supplied?
4. Do the numbers add up, with tax shown separately?
5. Is it clear when and how to pay?

Start from a template

Skip the blank page: try the simple invoice template, hourly invoice template or fixed price invoice template. Each one loads with example lines you can replace.