InstaBill is a free GST billing app that helps businesses create invoices, quotations, and purchase orders with ease. It also provides inventory management, expense tracking, and generates various reports such as sales by customers, products, purchase, expenses, debtors, inventory, and GST. The app is GST compliant with mandatory HSN/SAC codes and generates GSTR-1, GSTR-3B, CMP-08, and GSTR-2A reports. InstaBill is designed for small and large business owners, contractors, and freelancers who need a professional mobile invoice app. The app supports automation, which allows users to create and send invoices with payment links to customers automatically on a daily, weekly, or monthly basis. It also enables payment collection via NEFT, RTGS, net banking, wallet, and UPI payments. InstaBill is available on mobile and web browsers.