Business Editors/High-Tech Writers

CUPERTINO, Calif.--(BUSINESS WIRE)--Dec. 18, 2002

Portal Software, Inc. (Nasdaq:PRSF), a leading provider of billing and customer management software, today announced that Cell C, a South African mobile network operator, has selected Infranet(R), Portal's convergent billing solution, to enable value-based pricing for premium GSM and GPRS-based data and content services to its growing customer base of more than one million subscribers. Cell C is Portal's first mobile customer in the Southern African region and a strategic win for Portal in this new wireless market.

In order to take advantage of the rapidly expanding South African market for wireless services and gain competitive market share, Cell C needed a system that could manage billing for a wide range of premium services. Planned services include downloadable content, ring tones, games, and information and entertainment services delivered over GSM, SMS, MMS and GPRS. Portal's flexible billing platform will provide Cell C with the capability to quickly launch new products and services, support multiple pricing plans, and integrate cleanly with existing business systems.

"We chose Portal's billing platform because it will dramatically accelerate Cell C's time to market for the new and innovative services that our customers are demanding," said Themba Khumalo, Marketing Director, Cell C. "Deploying Portal will enable Cell C to charge for the value of these new and enhanced services which will allow us to create new value chains with third party content providers. Additionally, Portal's Infranet has proven to be more cost effective than competitive offerings and we believe the new billing platform will be essential in driving higher usage per user and increasing Cell C's competitive market share."

"Portal is excited to be working in the Southern African region and expanding our global reach through our support of Cell C," said Alan Laing, vice president and general manager EMEA, Portal Software. "The most agile mobile service providers are finding that profitability for new services is possible when they have flexibility built into their billing systems. Infranet gives Cell C the flexibility to rapidly create new services with rating based on virtually any parameter. With its focus on delivering new data services, Cell C will not only be able to deliver a better customer experience, but as importantly, keep their ongoing cost of operations predictable."

About Portal Software, Inc.

Portal Software develops product-based customer management and billing solutions for communications and content service providers. Portal's convergent platform enables service providers to deliver voice, data, video, and content services with multiple networks, payment models, pricing plans, and value chains. Portal's unique approach is designed to provide its customers superior return on innovation with maximum value and lower total cost of ownership. Customers include Vodafone, AOL Time Warner, Deutsche Telekom, TELUS, NTT, China Telecom, Reuters, Telstra, China Mobile, Telenor Mobil, Vivendi, and France Telecom.

About Cell C

Cell C is South Africa's first cellular provider operating a dual band GSM 900/1800 Mhz network, offering products and services to over one million subscribers. With a network capable of providing voice, data and future multimedia communications, Cell C is committed to providing subscribers with a full range of GSM services, based on the key principles of simplicity, choice and value. Cell C has achieved significant market share since it's launch in 2001. For more information, please visit www.cellc.co.za.

Note to Editors: Infranet and the Portal logo are U.S. registered trademarks, and Portal is a trademark of Portal Software, Inc. All statements made in this press release are made only as of the date set forth at the beginning of this release. Portal undertakes no obligation to update the information in the event facts or circumstances subsequently change.