Guide

How to invoice

An invoice is a dated request for payment for work you already agreed to do. For US freelancers, a clean invoice is usually enough — you do not need accounting software to get paid the first time.

Written for sole proprietors and small US shops billing in USD.

What every invoice should include

InvoiceForge is a free invoice generator that puts those fields on one page and builds a PDF in your browser.

When to send it

Send the invoice as soon as the deliverable is accepted — or on the schedule in your contract (weekly, at milestones, or at the end of the month). Do not wait for the client to “remind you.” The invoice is how they put you in accounts payable.

Pick payment terms you can live with

If a client pays slowly, invoice sooner, ask for a deposit, or shorten the next term. Put the due date on the PDF so nobody has to calculate “net 15” from an email timestamp.

Number invoices so you can find them later

Use a sequence you will not collide with: INV-20260922-14 or2026-014. Keep a simple list in a spreadsheet. When a client asks about “that invoice from March,” the number is the handle.

Follow up without guessing

  1. Day after the due date: a short note with the PDF attached again and the invoice number in the subject.
  2. A week later: ask if they need a W-9, a PO, or a different AP email.
  3. After that: pause new work until the account is current, if your contract allows it.

Do not invent tax language you do not understand. If you collect sales tax, say so on the line and keep the rate you actually owe. ReadUS sales tax on invoices for the high-level picture, then confirm with your state or a tax pro.

Create one now

Open the free invoice generator, fill the form, and download a PDF. A draft can stay in this browser if you want to finish later. Nothing is uploaded.