How to Write an Invoice: Step-by-Step Guide for Freelancers

A good invoice does two jobs: it gets you paid faster, and it makes you look professional. Whether you are a freelancer, designer, developer or consultant, every invoice you send should contain the same core elements. Here is exactly what to put on an invoice — and what to leave out.

1. What every invoice must include

• The word “Invoice” and a unique invoice number (e.g. INV-2026-014) so both sides can reference it in payments and accounting.
• Your business details — name or company, email, and address. In many countries your tax ID (VAT/GST/ABN/EIN) is also required on tax invoices.
• Your client's details — the legal name of the company or person being billed, plus their address.
• Dates — the issue date and the payment due date. “Net 14” means payment is due 14 days after the issue date.
• Itemized line items — a clear description, the quantity, and the unit price for each deliverable. Vague lines like “work done” are the #1 reason invoices get delayed.
• Subtotal, tax and total — show the math. Apply any discount before tax if your local rules require it.
• Payment instructions — bank account, IBAN/SWIFT, payment links, or “Pay by card” details, plus the currency you expect to receive.

2. How to number invoices

Use a simple, consistent scheme that never repeats: INV-YYYY-NNN (year + counter) works well for most small businesses. If you invoice several clients, some freelancers add a client prefix, e.g. INV-ACME-2026-003. Never reuse or “skip back” numbers — tax authorities in many countries expect sequential, gap-free numbering.

3. Choosing payment terms

Net 14 is the freelance default. Net 7 or “due on receipt” is reasonable for small projects or new clients; Net 30 is common for larger companies with slow accounts-payable cycles. Whatever you choose, put the exact due date on the invoice — “payment terms: net 14” alone forces the client to calculate it.

4. Taxes and discounts

If you are registered for sales tax, VAT or GST, state the rate explicitly (e.g. “VAT 20%”) and show the tax amount separately. Discounts should appear as their own line so your client's accounting software can match the numbers. When a discount applies, most jurisdictions expect tax to be calculated on the discounted amount.

5. Create your first invoice in 60 seconds

You can generate a clean, professional invoice right now: open the free online invoice generator, fill in the form, and download a watermark-free PDF. Everything runs in your browser — no account, and your client data never leaves your device.