What to include on an invoice: the complete checklist

How to build a complete invoice in five steps

1. Add the heading and number. Title the document “Invoice” (or “Tax invoice” where required) and give it a unique number and date.
2. Add both parties. Enter your legal or trading name and address, tax number if registered, and your customer’s name and billing address.
3. List what you supplied. Write specific line items with quantity, unit price and totals, then add tax if you charge it.
4. State when and how to pay. Give a due date, payment methods and a reference, then add any late-payment terms from your agreement.
5. Check, save and send. Check the totals, export a PDF, and send it to the person who approves payment.

The fields every invoice needs

Whatever country you work in, a document that gets paid without questions carries the same core information. Think of it as answering the customer’s questions before they ask them.

• The word “Invoice” in a clear heading, so nobody mistakes it for a quote or a statement. In Australia a document that qualifies for GST credits must say “tax invoice”.
• A unique invoice number. It lets you and your customer refer to one document without confusion. See invoice numbering best practices.
• The invoice date and, separately, the date of supply if the work was delivered on a different day.
• Your business details: legal or trading name, address, email or phone, and any registration number your country asks for (VAT, GST, ABN, EIN where relevant).
• Your customer’s details: name or company name and billing address. Add their tax number if they are VAT or GST registered and need it to reclaim tax.
• A description of each item, with quantity, unit price and line total. Specific wording such as “Logo design, three concepts, two revision rounds” gets paid faster than “Design work”.
• Subtotal, tax and total, with the currency shown clearly.
• The due date or payment terms, for example “Due 14 November 2026” rather than only “Net 30”.
• How to pay: bank details, a payment link or cheque instructions, plus the reference the customer should quote.

Details that reduce disputes

These are not legal requirements in most places, but each one removes a reason to delay payment.

• The customer’s purchase order number or project reference. Many accounts teams cannot pay without it.
• Late payment terms, such as a fixed fee or monthly interest, if they are in your agreement. See late fees and interest on invoices.
• A deposit or part-payment line if some of the amount is already paid. See deposits and milestone billing.
• A short thank-you or note and a named contact for billing questions.
• Your logo and consistent colours. They make the document look like it came from a real business, which it did.

Extra items by country

Tax rules decide what a valid tax invoice looks like. Registered businesses need a compliant invoice to claim back the tax they paid, so customers will ask for it. The summaries below are a starting point only. Always read the linked official guidance.

United States

There is no federal rule that prescribes an invoice layout. Sales tax is set by states, so show the tax line if you collect it. If you are paid as a contractor, keep a copy for your own records and expect to give your customer a Form W-9. See W-9 and 1099 explained.

United Kingdom

A VAT invoice normally shows a unique number, the tax point, your name, address and VAT number, the customer’s name and address, a description, the price excluding VAT, the VAT rate and amount, and the total. See the UK VAT invoice requirements.

Canada

For sales to GST/HST registrants, the information needed depends on the invoice total. Under CA$100 needs less; CA$500 or more needs the buyer’s name, a description and payment terms. See GST/HST invoice requirements.

Australia

A tax invoice is needed when the sale is more than A$82.50 including GST, if the customer asks for one. It must show your ABN. See ABN and invoicing.

New Zealand

The old “tax invoice” is now “taxable supply information”, with three value bands (up to NZ$200, over NZ$200 to NZ$1,000, over NZ$1,000). See taxable supply information.

European Union

The VAT Directive lists the mandatory content: sequential number, date, VAT identification numbers, names and addresses, the nature and quantity of the goods or services, the date of supply, the taxable amount per rate, the rate, the VAT amount and any exemption or reverse-charge reference. Member states add their own rules. See reverse charge explained.

Common mistakes that delay payment

1. Sending the invoice to the wrong person. Ask who approves invoices and send it there, with the project owner copied.
2. Vague due dates. “On receipt” and “soon” are not dates.
3. Missing tax number on a business-to-business invoice. The customer’s finance team may reject it.
4. Totals that do not add up. Rounding per line versus on the total gives small differences. Pick one method and use it consistently.
5. Changing details after sending. Issue a credit note and a new invoice instead of editing the original.
6. No payment instructions. A customer who has to ask for your bank details will do it next week.

Use the checklist with a free generator

The InvoiceDesk invoice generator has fields for every item above and country pages that label tax fields correctly for the UK, Canada, Australia, New Zealand and the EU. It runs in your browser, so nothing you type is uploaded.

Glossary

Tax point

The date a supply is treated as happening for tax, often the invoice or payment date.

Purchase order (PO)

A document from the buyer authorising a purchase. Quote its number on your invoice.

Payment terms

The agreed time and conditions for payment, such as Net 14 or due on receipt.

Related topics

• invoice checklist
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