Wikipedia
Bill.com is a US-based cash flow management software system, provided as a software as a service that integrates with accounting and banking systems. It is intended to serve as a command and control dashboard for cash flow, by businesses, accounting firms and banks. Bill.com works with third-party accounting package such as QuickBooks, not as a standalone product. Bill.com offers sync or integration with accounting software packages such as QuickBooks, Xero, NetSuite, and Intacct.
The product is also widely used by banks to offer online banking services to businesses. Bank of America Merrill Lynch uses Bill.com for payments technology in their CashPro BillPay product. PNC Bank uses Bill.com in its online services for small businesses, including its Cash Flow Insight product that syncs with QuickBooks.