Exhibit 99.1 IBASIS, INC. AND THE BANK OF NEW YORK, AS TRUSTEE INDENTURE DATED AS OF JUNE 18, 2004 6 3/4% CONVERTIBLE SUBORDINATED NOTES DUE 2009Indenture • June 29th, 2004 • Ibasis Inc • Telephone communications (no radiotelephone) • New York
Contract Type FiledJune 29th, 2004 Company Industry Jurisdiction
iBASIS, INC. ANDRegistration Rights Agreement • June 29th, 2004 • Ibasis Inc • Telephone communications (no radiotelephone) • New York
Contract Type FiledJune 29th, 2004 Company Industry Jurisdiction
EXECUTION COPY IBASIS, INC., THE SUBSIDIARY GUARANTORS NAMED HEREIN AND THE BANK OF NEW YORK, AS TRUSTEE INDENTURE DATED AS OF JUNE 18, 2004 8% SECURED CONVERTIBLE NOTES DUE 2007 TABLE OF CONTENTSIndenture • June 29th, 2004 • Ibasis Inc • Telephone communications (no radiotelephone) • New York
Contract Type FiledJune 29th, 2004 Company Industry Jurisdiction
by and among iBASIS, INC. andNote Purchase Agreement • June 29th, 2004 • Ibasis Inc • Telephone communications (no radiotelephone)
Contract Type FiledJune 29th, 2004 Company Industry
2004 WARRANT AND REGISTRATION RIGHTS AGREEMENT DATED AS OF JUNE 18, 2004 WARRANT AND REGISTRATION RIGHTS AGREEMENTWarrant and Registration Rights Agreement • June 29th, 2004 • Ibasis Inc • Telephone communications (no radiotelephone) • Massachusetts
Contract Type FiledJune 29th, 2004 Company Industry Jurisdiction