How to write an invoice that gets paid

The short answer

An invoice needs your details, the client’s details, a unique number, the issue and due dates, an itemised list of what you supplied, tax shown separately, the total due and payment instructions. If you are registered for GST or VAT, add your registration number and follow your country’s tax invoice rules.

Step by step

1. Add your business details. Your legal or trading name, address, contact details and, if registered, your GST/VAT number.
2. Add the client. The person or company you are billing, their address and, for business clients, their tax ID where required.
3. Give it a unique number and dates. Use a sequential number such as INV-1001, the issue date and the date payment is due.
4. List what you are charging for. One line per product or service with a clear description, quantity, rate and amount.
5. Show tax and discounts separately. Subtotal, discount, each tax at its rate, then the total due.
6. Say how to pay. Bank details, a payment link or UPI ID, and your payment terms.
7. Send it as a PDF and keep a copy. A PDF looks the same everywhere and cannot be edited by accident.

The invoice generator walks through exactly these steps and checks the result before you download it.

Invoice, receipt, quote or credit note?

In InvoiceKit you can convert one into the next from the Documents page: quote → invoice, invoice → receipt or credit note.

Payment terms that work

Be specific. “Due on 15 November 2026” or “Net 15” leaves less room for delay than “payable soon”. Shorter terms (7 to 15 days) suit small jobs and new clients; larger companies often run payment cycles of 30 days or more and may require a purchase order (PO) number on the invoice, so ask for it up front.

• Deposits: for large jobs, invoice 30–50% up front and the rest on delivery.
• Early payment: if you offer a discount for paying early, state it on the invoice with the deadline.
• Late payment: some countries let businesses charge statutory interest on late business invoices. Check your local rules before adding a late fee.

Discount first, then tax

A discount is normally taken from the subtotal and tax is calculated on the discounted amount. If your prices already include tax (common in retail in the UK, Australia and New Zealand), the tax is worked back out of the price. InvoiceKit does both and rounds each tax to the nearest cent or paisa.

Common mistakes that delay payment

• Reusing or skipping invoice numbers.
• Vague descriptions such as “services”. Say what was delivered and the period it covers.
• Missing payment details, so the client has to ask how to pay.
• Wrong legal name or missing PO number, so the client’s accounts team rejects it.
• Invoicing late. Send it the day the work or milestone is done, and follow up politely a few days after the due date.

Rules by country

Tax invoice rules differ. Our country guides list what must appear on an invoice, the current rates and the tax-ID format, with links to the official sources:

• India (GST)
• United States
• Canada (GST/HST)
• United Kingdom (VAT)
• Australia (GST)
• New Zealand (GST)
• South Africa (VAT)
• Nigeria (VAT)
• Kenya (VAT)

Keep your records

Keep a copy of every invoice and when it was paid. Many countries require business records to be kept for five to eight years. InvoiceKit keeps your history in this browser; download a backup from Documents regularly.