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What to Include on an Invoice: The Complete Checklist

Clients pay invoices they understand and question invoices they don't. These are the fields that separate a professional invoice from a payment delay — plus the legal extras for VAT/GST-registered businesses.

The 8 fields every invoice needs

These eight fields belong on every invoice, everywhere:

1. Invoice number — unique, sequential, never reused. INV-2026-001 is a solid format.
2. Your business details — name, address, email, phone. Add your logo for instant credibility.
3. Client details — the legal billing name and address, not just your day-to-day contact.
4. Invoice date — the day you issue it. This starts the payment clock.
5. Due date — a real calendar date. 'Due on receipt' is fine for small jobs; otherwise give 7–30 days.
6. Line items — each product or service with description, quantity, rate, and amount.
7. Totals — subtotal, then tax and discounts as separate lines, then the grand total.
8. Payment instructions — exactly how to pay: account numbers, payment links, or 'payable to' names.

3 fields most freelancers forget

Three fields that most freelancers skip — and shouldn't:

• PO number — if your client uses purchase orders, the invoice dies in procurement without it.
• Late fee policy — '1.5% per month on overdue balances' in writing is enforceable; a verbal warning isn't.
• Thank-you note — one line ('Thanks for your business!') measurably improves payment speed. It's free.

Tax extras for VAT/GST-registered businesses

If you're VAT or GST registered, tax authorities require extra fields: your tax registration number, the tax rate per line item, tax amounts shown separately, and totals with and without tax. Label matters too — Australia requires the words 'Tax invoice', South Africa the same, and the UK has specific full/simplified/modified formats.

When in doubt, include more tax detail rather than less. An invoice your client's accountant can't use is an invoice that doesn't get paid on time.