You finish a project. You need to invoice. You don't have accounting software because you don't need accounting software — you have five clients, not five hundred. The simple invoice maker for freelancers angle is built around exactly this: clean invoice in under two minutes, no monthly cost, no learning curve.
Small business owners
You're running the whole show — sales, ops, admin, billing. You bill irregularly and you don't want £29/month going out for a tool you use four times a month. The Invoice Maker covers the billing job without the subscription.