UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                                    FORM 8-K

                                 CURRENT REPORT
                     PURSUANT TO SECTION 13 OR 15(d) OF THE
                         SECURITIES EXCHANGE ACT OF 1934

                                 April 28, 2008
                               -------------------
                Date of Report (Date of earliest event reported)
                               -------------------

                                  iBASIS, INC.
                              ---------------------
               (Exact Name of Registrant as Specified in Charter)

      DELAWARE                     000-27127               04-3332534
(State or Other Jurisdiction  (Commission File Number)    (IRS Employer
   of Incorporation)                                     Identification No.)

                     20 Second Avenue, Burlington, MA 01803
            ---------------------------------------------------------
               (Address of Principal Executive Offices) (Zip Code)

                                 (781) 505-7500
              (Registrant's telephone number, including area code)

      Check the appropriate box below if the Form 8-K filing is intended to
simultaneously satisfy the filing obligation of the registrant under any of the
following provisions (see General Instruction A.2. below):

[_]  Written communications pursuant to Rule 425 under the Securities Act (17
     CFR 230.425)

[_]  Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR
     240.14a-12)

[_]  Pre-commencement communications pursuant to Rule 14d-2(b) under the
     Exchange Act (17 CFR 240.14d-2(b))

[_]  Pre-commencement communications pursuant to Rule 13e-4(c) under the
     Exchange Act (17 CFR 240.13e-4(c))






Item 2.03. Creation of a Direct Financial Obligation or an Obligation under an
Off-Balance Sheet Arrangement of a Registrant.

      On April 28, 2008, iBasis, Inc. ("iBasis") and Silicon Valley Bank (the
"Lender") entered into a First Loan Modification Agreement (the "Loan
Modification Agreement") to that certain Second Amended and Restated Loan and
Security Agreement (the "Original Loan Agreement," and as amended by the Loan
Modification Agreement, the "Amended Loan Agreement") between the parties dated
as of October 2, 2007. iBasis entered into the Loan Modification Agreement to,
among other things, increase the maximum amount of the revolving facility from
$35,000,000 to $50,000,000, to revise certain financial covenants contained in
the Original Loan Agreement, and to permit iBasis to repurchase up to
$15,000,000 of its capital stock, pursuant to a stock repurchase program
approved by its board of directors.

      Pursuant to the Amended Loan Agreement, iBasis may borrow up to
$50,000,000 from time to time under a secured revolving credit facility for a
two-year period which commenced October 2, 2007. The interest payable on amounts
drawn under this revolving credit facility are based on either the Lender's
prime rate, plus a margin, or LIBOR, plus a margin. The revolving credit
facility is also guaranteed by iBasis Global, Inc., iBasis Retail, Inc., iBasis
Securities Corporation and KPN International Network Services, Inc., all of
which are wholly-owned subsidiaries of iBasis. The revolving credit facility is
secured by a first priority lien and security interest in the assets of iBasis
and such guarantors. In addition, iBasis has pledged two-thirds of all its
shares of KPN Global Carrier Services B.V., which is a wholly-owned subsidiary
of iBasis, as collateral for the revolving credit facility. Pursuant to the
terms of the Amended Loan Agreement, iBasis shall use the proceeds solely as (i)
working capital, (ii) to fund its general business requirements, and (iii) to
fund the dividend declared by iBasis in connection with the transactions with
KPN B.V.

Item 9.01 Financial Statements and Exhibits.

(d) Exhibits

Exhibit No.     Description
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99.1            First Loan Modification Agreement dated as of April 28, 2008
                between Silicon Valley Bank and iBasis, Inc.






                                   SIGNATURES

      Pursuant to the requirements of the Securities Exchange Act of 1934, the
registrant has duly caused this report to be signed on its behalf by the
undersigned hereunto duly authorized.


Date: May 2, 2008                    iBasis, Inc.

                               By:/s/ Mark S. Flynn
                                      Chief Legal Officer and
                                      Corporate Secretary
                                      ----------------------------