How to write an invoice, step by step

A clear invoice gets paid faster. Here is what to include, in order.

1. Put your own details at the top

Start with your business name, address and contact details. If you are VAT-registered, add your VAT number; if your business is registered with a chamber of commerce or companies register, add that number too. A logo is optional but makes the invoice easy to recognise.

2. Add the client

Write the name and billing address of the person or company you are charging. For business customers in another EU country, include their VAT number — you will need it for reverse-charge invoices.

3. Give it a unique number

Every invoice needs a number that is never reused. A simple, gap-free sequence such as 2026-001, 2026-002 works well and is what most tax authorities expect.

4. Set the invoice date and due date

The invoice date is the day you issue it. The due date tells the client when payment is expected — 14 or 30 days are common. Stating it clearly reduces late payments.

5. List what you supplied

Use one line per product or service, with a description specific enough that the client recognises it, the quantity, the unit price and the VAT rate that applies to that line.

6. Show the totals

  • Subtotal before VAT
  • Any discount
  • VAT amount per rate
  • Total amount due

7. Explain how to pay

Add your IBAN or other payment details and your payment terms. A short thank-you note at the end is a nice touch.

Do it in two minutes

The free Invoice Generator King generator walks you through exactly these steps, calculates VAT per line and gives you a PDF ready to send.

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