Billfinch
How to write an invoice
A good invoice is complete, easy to follow, and consistent with the work you agreed to. Walk through the steps below, then use the calculator for the totals.
1. Put both parties at the top
Your business name, address, email, and phone (and a tax ID if you use one). The client's name, a contact, and their address. If you have a logo, it belongs here, not in the totals.
2. Number and date it
Give the invoice a unique number and an issue date. Add payment terms and the resulting due date. INV-1042 issued November 10, 2026 on Net 30 is due December 10, 2026.
3. Itemize the work
Each line needs a description the client will recognize, a quantity, a rate, and a line amount (quantity × rate). Hourly work should show the hours and the hourly rate. Fixed fees can use a quantity of 1.
4. Add discount, tax, and shipping in that order
A percentage discount usually applies to the subtotal (or to the lines you mark). Tax is then calculated on the taxable amount after the discount. Shipping is added unless you have agreed it is inclusive. Show each row, then a total and a balance due if something has already been paid.
Worked example
32 hours at $95 = $3,040, plus a $2,400 logo, plus $75 of non-taxable licenses. Subtotal $5,515. A 5% discount is $275.75. Tax at 8.25% applies only to the discounted taxable lines ($5,168.00 base) and is $426.36. Total due: $5,665.61. That is the sample invoice on this site.
See a sample invoice
5. Say how to pay, then send it
List accepted methods and any account or memo details. Send a PDF, not a screenshot of a spreadsheet. Keep a copy; a generator that does not store invoices means the PDF you download is the record.
See also a freelancer invoice and a contractor invoice.
Questions people ask
How do you write an invoice?
List your details and the client's, give the invoice a unique number and dates, itemize the work with quantities and rates, add discount, tax, and shipping, show the total and due date, and explain how to pay.
What payment terms should I use?
Net 30 (due 30 days after the issue date) is common. Net 15, due on receipt, or a deposit plus a balance are also used. Write the term and the actual due date on the invoice so there is no guesswork.
Do I need an invoice number?
Yes. Use a unique number on every invoice, such as INV-1042, and do not reuse it. A short prefix plus a rising number keeps records clear when you have more than one client.