Press Release

ACI Worldwide Inc To Present At William Blair Small Cap Growth Stock Conference

September 26, 2007
ACI Worldwide Inc To Present At William Blair Small Cap Growth Stock ConferenceThe presentation will be webcast by Wall Street Webcasting at 3:20 p.m. (EDT) and interested persons may access a real-time broadcast at: www.aciworldwide.com/investors.
About ACI Worldwide, Inc.

Every second of every day, ACI Worldwide solutions are at work processing electronic payments, managing risk, automating back office systems and providing application infrastructure services.   ACI is a leading international provider of solutions for banking, retail and cross-industry systems.  ACI serves more than 800 customers in 84 countries including many of the world's largest financial institutions, retailers and payment processors.  Visit ACI Worldwide at www.aciworldwide.com.

Investor Contacts

John Kraft, Head of Strategy & Finance
Email: john.kraft@aciworldwide.com

Global Headquarters:
ACI Worldwide
2811 Ponce de Leon Blvd, PH1
Coral Gables, FL 33134