Guides

What to put on an invoice: a plain checklist

Updated October 15, 2026

A good invoice answers four questions for your customer: who is billing me, for what, how much, and when do I pay.

The checklist

• The word "Invoice" at the top, so it isn't mistaken for a quote or a receipt.
• Invoice number. Any simple count works: 001, 002, 003.
• Invoice date. The day you send it.
• Your business name and contact info.
• Your customer's name and email (and business name if they have one).
• What you did. One line per service, with the price. If the customer gave you a PO number, add it.
• Total owed. Add the lines up, and show tax only if you charge it.
• Due date. An actual date, like "Due November 14."
• How to pay. A pay link or button is best.
• Late fee wording. One sentence stating the fee and when it starts.

A simple example

Invoice 014. October 15, 2026. Due October 29, 2026.

Office cleaning, week of Oct 5: $480.

Window wash, front entrance: $60.

Total: $540.

"A $25 late fee applies if unpaid 7 days after the due date."

Taxes

Whether you charge sales tax depends on what you sell and where. This is general information and not legal or tax advice, so check with your state or a local accountant.

How Dunn helps

Dunn's New invoice form covers every item on this checklist: it numbers and dates the invoice for you, adds your business details, and asks for the client, your services (saved for next time), the due date, a PO number and an optional late fee. Then it sends it in your name with a pay button, and reminds your customer if it's late.

Quick answers

Does an invoice have to look fancy?
No. Clear beats pretty.

Should I include a PO number?
Yes, if the customer gave you one. Bigger companies often won't pay without it.

Can I add a late fee?
Yes, if you tell the customer before the work. See How to charge a late fee on an invoice.