What's the worst part of getting paid as a freelancer or agency?

Honest question for anyone who bills clients by the hour.

For me the work was never the problem. It was everything around the money. Time logged in one tool, invoices built in another, and then writing "just following up on that invoice :)" for the third time.

I'm building Hoursmith to pull that whole loop into one place, from timer to paid invoice, and we're launching here soon. Before we do, I want to hear the real pain:

• What part of getting paid annoys you most? Chasing late payers, the admin, your tools not talking to each other, something else?

• What does your current setup look like, and where does it leak time or money?

I'll share what we've built in the replies for anyone curious. Mostly I just want to know what's still broken so I can fix the right things.