EXHIBIT 99.1

Certification of Chief Executive Officer and Chief Financial Officer Pursuant to 18 U.S.C. Section 1350, as Adopted Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002

In connection with the Quarterly Report of Portal Software, Inc. (the “Company”) on Form 10-Q for the period ended April 30, 2003 as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, John E. Little, Chief Executive Officer of the Company, certify, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that:

(1) The Report fully complies with the requirements of section 13(a) or 15(d) of the Securities Exchange Act of 1934; and

(2) The information contained in the Report fairly presents, in all material respects, the financial condition and result of operations of the Company.

Date: June 13, 2003
	By:	/s/    JOHN E. LITTLE
		John E. Little Chief Executive Officer

In connection with the Quarterly Report of Portal Software, Inc. (the “Company”) on Form 10-Q for the period ended April 30, 2003 as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, Howard A. Bain III, Chief Financial Officer of the Company, certify, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that:

(1) The Report fully complies with the requirements of section 13(a) or 15(d) of the Securities Exchange Act of 1934; and

(2) The information contained in the Report fairly presents, in all material respects, the financial condition and result of operations of the Company.

Date: June 13, 2003
	By:	/s/    HOWARD A. BAIN III
		Howard A. Bain III Chief Financial Officer