As an online freelancer, I need to be able to bill clients from all over the world. Wave allows me to create my own customized invoice for that, and break down the billing for each individual task. I recently held double positions within a company and I was able to bill for each department on one invoice. It allows me to create, edit, approve, and send invoices, even to send reminders to pay. Once paid I can then record the payment and send a receipt to the client for their records. This is very important as a freelancer because not everyone pays on the same schedule and keeping track of payments could be a hassle otherwise.