A public address for the invoice link
Pro can use a short address such as northline.wireinvoice.com. The client opens the invoice there. Free does not include it.
What it is
The address is the front of the link you send. The client still does not need an account. They open the invoice and download the PDF.
The rules
Three to thirty-two letters and numbers. No spaces. Names such as admin, www, app, and api are reserved. The address is part of Pro, with the unlimited invoices.