Online invoicing startup Bill.com announced a new round of $15.5 million in Series D funding today, boosting the total raised to $40 million:

“The financing round included new investor Financial Partners Fund (FPF), a unit of Citi Capital Advisors, and existing Bill.com investors including DCM, Emergence Capital Partners, August Capital, Jafco Ventures and Total Technology Ventures. Bill.com will use the additional capital to scale operations in support of continued customer growth and for product development and marketing purposes.”

The company also shared some growth figures for 2011:

• Grew over 300% 
• Added tens of thousands of vendors and customers to its network 
• Currently holds over $3 billion under management