Documentation / Accounting & Financial Management Customer Invoicing & Progressive BOQ Billing Updated 2026-08-31 Copy link Print In this section Ways to create customer invoices WindoorERP has exactly two ways to invoice a customer, and both can be started… Create a standard customer invoice The standard customer invoice is the everyday billing document: draft it… Send a pro-forma invoice A pro-forma invoice is the document a customer needs before the real invoice… Bill contract progress with a BOQ invoice A BOQ invoice is a claim for this period's progress on a contract. Its lines… Take a contract advance through a BOQ invoice Window contracts start with money: an advance on signature, recovered piece by… Process credit notes, register customer payments, and manage customer accounts Money comes back to a fabricator two ways: as a receipt against an invoice, or… Was this article helpful? Yes No What was missing? Send feedback Thanks — your feedback helps. Running a window or door factory? Ask for a demo