A billing profile is the invoicing identity of a Project: the legal name, the address, the tax ID, and an optional PO number. These details go on the invoices. Open Billing in the Customer account group of the sidebar. You need the Billing admin role to change a billing profile.
Every customer account starts with one default billing profile. Each new Project uses the default profile. Use more profiles when different legal entities, or your clients, pay for different Projects.
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