How to write an invoice

An invoice is a request for payment. It tells a customer what they owe, why, and by when. A clear one gets paid faster.

What every invoice needs

These are the basics. Some places and industries require more, so check local rules.

• The word Invoice, so no one mistakes it for a quote
• A unique invoice number
• Your name or business name and contact details
• The customer's name and billing details
• The invoice date and the payment due date
• A description of each product or service, with quantity and price
• Subtotal, tax if it applies, and the total due
• How to pay, and any payment terms

Step by step

Start with your own details and the customer's. Give the invoice a number and today's date. Add each item as its own line, with a quantity and a price. Add tax if you charge it, check the total, and write the due date and payment instructions at the bottom.

Send it as soon as the work is done or the goods are delivered. The sooner it goes out, the sooner it can be paid.

Numbering invoices

Use a simple system you will keep to. A running number like 0001, 0002, or a year and number like 2026-014, both work. Do not reuse numbers and avoid gaps you cannot explain.

Mistakes that delay payment

• No due date, so the customer pays whenever
• Vague descriptions like Services, with no detail
• Missing or wrong customer details, so accounts payable rejects it
• No payment instructions
• Sending it to the wrong person

Quotes, invoices and receipts

A quote says what you plan to charge. An invoice asks for payment. A receipt confirms payment was made. Read more in our guide on the difference between an invoice and a receipt.

Questions

Free tool: Invoice Total Calculator

General information, not legal, tax, or accounting advice. Rules vary by place.