UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 15 CERTIFICATION AND NOTICE OF TERMINATION OF REGISTRATION UNDER SECTION 12(g) OF THE SECURITIES EXCHANGE ACT OF 1934 OR SUSPENSION OF DUTY TO FILE REPORTS UNDER SECTIONS 13 AND 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934. Commission File Number 333-77054-12 CREDIT SUISSE FIRST BOSTON MORTGAGE SECURITIES CORP. (Exact name of registrant as specified in its charter) 11 Madison Avenue, New York, NY 10010 (212)325-2000 (Address, including zip code, and telephone number, including area code, of registrant's principal executive offices) Credit Suisse First Boston Mortgage Securities Corp., CSFB Mortgage-Backed Pass-Through Certificates, Series 2002-S12 (Title of each class of securities covered by this Form) None (Titles of all other classes of securities for which a duty to file reports under section 13(a) or 15(d) remains) Please place an X in the box(es) to designate, the appropriate rule provision(s) relied upon to terminate or suspend the duty to file reports: Rule 12g-4(a)(1)(i) Rule 12h-3(b)(1)(i) X Rule 12g-4(a)(1)(ii) Rule 12h-3(b)(1)(ii) Rule 12g-4(a)(2)(i) Rule 12h-3(b)(2)(i) Rule 12g-4(a)(2)(ii) Rule 12h-3(b)(2)(ii) Rule 15d-6 X Approximate number of holders of record as of the certification or notice date: 38 Pursuant to the requirements of the Securities Exchange Act of 1934, Credit Suisse First Boston Mortgage Securities Corp. has caused this certification/notice to be signed on its behalf by the undersigned duly authorized person. JPMorgan Chase Bank in its capacity as Trustee under the Pooling and Servicing Agreement on behalf of Credit Suisse First Boston Mortgage Securities Corp., Registrant By: /s/ Andreas Auer ------------------------------------------------------- Name: Andreas Auer Title: Vice President Date: January 29, 2003