How to Write an Invoice
To write an invoice, put your business name and contact details at the top, add the client below them, then give the document a unique invoice number, an issue date and a due date. List each item with a description, quantity and price, add any tax, show the total, and include how to pay you.
Skip ahead — generate your invoice nowAn invoice is a written request for payment. A good one leaves no room for questions: the client can see who is billing them, for what, how much, and how to pay. Below, each part of the invoice is explained in the order it appears on the page, so you understand what every field is for as you write it.
Step 1 — Add your business details and logo
Start at the top with who is sending the invoice: your business or your own name, address, email and phone. If you have a logo, place it here so the document looks like it came from you. This block is what tells the client whom they are paying and where to reach you with questions, so keep it accurate and consistent across every invoice you send.
Step 2 — Add your client's details
Below your own details, write the client's legal or business name and their billing address. Add a contact person and email if you have one, because that is who approves and routes the payment. For a company client, use the exact registered name they ask to be billed under — it has to match their records for the invoice to clear their accounts team without a query.
Step 3 — Give it an invoice number and dates
Every invoice needs a unique invoice number (for example INV-0001, then INV-0002). The number is how you and the client refer to one specific bill and how you keep your records in order. Add the issue date and a due date. The due date comes from your payment terms: "Net 30" means payment is due 30 days after the issue date — Net 7 and Net 14 work the same way for shorter windows.
Step 4 — List the line items
In the table, give each product or service its own row with a clear description, the quantity, and the unit price. The line total is quantity times unit price, and the subtotal is every line added up. Write descriptions the client will recognise from the work or order — "Logo design — final files" reads better than "design", and a specific line is far less likely to be questioned or delayed.
Step 5 — Add tax, VAT, discount or shipping
If you charge sales tax, VAT or GST, add it as its own line so the client can see the rate and amount. A VAT or Tax ID is the registration number some countries require you to show. You can apply one tax rate to the whole subtotal, set a rate per line when items are taxed differently, or quote tax-inclusive prices. Subtract any discount and add shipping here before the final total.
Step 6 — Add payment details
State exactly how you want to be paid. For a bank transfer, include the account name, account number and sort code or IBAN/SWIFT. If you take cards or online payments, add a payment link or note the methods you accept. The easier you make it to pay, the faster you get paid, so spell this out rather than assuming the client already has your details.
Step 7 — Add notes and terms, then send it
Close with a short note or your terms: a thank-you line, any late-payment charge, or a project reference. Check the totals and the client name once, then send the invoice as a PDF by email so it cannot be edited in transit. Keep your own copy for your records. With this tool you can fill every field above and download the PDF free — no signup, no watermark, and your data stays in your browser.
What to include on an invoice
Use this as a checklist while you write. The required column is a general guide; some fields are only required once you are registered for tax or when a client asks for them.
| Field | What it is | Required? |
|---|---|---|
| Your business details | Name, address and contact info of the sender | Yes |
| Client details | Who is being billed and their billing address | Yes |
| Invoice number | A unique reference for this one invoice | Yes |
| Issue and due dates | When it was sent and when payment is due | Yes |
| Line items | Description, quantity and unit price per row | Yes |
| Tax / VAT | Tax rate and amount, plus your tax ID if registered | If registered |
| Total amount due | Subtotal, tax and the final amount to pay | Yes |
| Payment details | Bank details or a payment link and accepted methods | Yes |
| Notes / terms | Payment terms, late fees or a short message | Optional |
Frequently asked questions
What needs to be on an invoice?
At minimum: your business name and contact details, the client’s name and address, a unique invoice number, the issue date and due date, a list of items with descriptions and prices, any tax, the total amount due, and how to pay. If you are registered for VAT or sales tax, show your tax ID and the tax rate as a separate line. Anything else — a logo, a purchase-order number, payment terms or a note — is optional but helps the client process the invoice and pay on time.
What does Net 30 mean on an invoice?
Net 30 is a payment term meaning the full amount is due within 30 days of the invoice issue date. Net 7 and Net 14 mean 7 and 14 days. The "net" simply refers to the total payable with no early-payment discount applied. Choose the term that fits your cash flow and the client relationship, write it next to the due date, and the date itself removes any doubt about when payment is expected.
How do I number my invoices?
Use a simple sequence that always goes up and never repeats, such as INV-0001, INV-0002, INV-0003. Some people add the year (2026-001) or a client code. The exact format does not matter — what matters is that each number is unique and the series has no gaps, because that is how you track which invoices are paid, find one quickly, and keep clean records for tax time.
Do I have to charge tax on an invoice?
It depends on where you are, what you sell and whether you are registered. In the US, sales tax rules vary by state and by the type of product or service. In the UK and EU you charge VAT once you are VAT-registered. In many places small or unregistered sellers do not add tax at all. Check the rules for your location, and when in doubt ask an accountant — this page explains the fields, not your tax obligations.
Can I write an invoice as a sole proprietor without a company?
Yes. You do not need a registered company to invoice. As a sole proprietor or freelancer you can invoice under your own legal name and address in place of a business name. Include the same essentials — your details, the client, a number, dates, items and how to pay. Add a tax ID only if you have one and are required to show it. Many people start invoicing this way before they ever register a business.