The client never gets an account. A quote lives on its own unguessable URL; accepting it raises the invoice immediately, and the card payment happens on that same page. On your side you can see it land — sent, opened, accepted, paid, each with a timestamp — and the chasing runs on a schedule you set. Numbering never repeats. Delete a draft and the next document still takes the next number. There is no PDF library. Every browser and phone already prints to PDF better than a bundled renderer would, and the pages are set up for it. The demo includes the expensive mistake — an accepted quote whose invoice is still sitting in draft, which is the thing freelancers actually forget.