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

                                  SCHEDULE 13G

                    Under the Securities Exchange Act of 1934

                                (Amendment No. __1__ )*


                                Open Text Corp.
--------------------------------------------------------------------------------
                                (Name of Issuer)


                                  Common Stock
--------------------------------------------------------------------------------
                         (Title of Class of Securities)


                                   683715106
--------------------------------------------------------------------------------
                                 (CUSIP Number)



                               February 28, 2006
--------------------------------------------------------------------------------
             (Date of Event Which Requires Filing of this Statement)


Check the appropriate box to designate the rule pursuant to which this Schedule
is filed:

         [ X ]    Rule 13d-1(b)

         [   ]   Rule 13d-1(c)

         [   ]   Rule 13d-1(d)


*The remainder of this cover page shall be filled out for a reporting person's
initial filing on this form with respect to the subject class of securities,
and for any subsequent amendment containing information which would alter the
disclosures provided in a prior cover page.

The information required in the remainder of this cover page shall not be
deemed to be "filed" for the purpose of Section 18 of the Securities Exchange
Act of 1934 ("Act") or otherwise subject to the liabilities of that section of
the Act but shall be subject to all other provisions of the Act (however, see
the Notes).

                                  SCHEDULE 13G

CUSIP No.         683715106

       
----------------------------------------------------------------------------------------------------------------------------

          1.   Names of Reporting Persons.  I.R.S.  Identification Nos. of above
               persons (entities only).
               AMVESCAP PLC
               AIM Advisors, Inc.
               AIM Capital Management, Inc.
               AIM Funds Management, Inc.

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          2.   Check the Appropriate Box if a Member of a Group (see
               Instructions)
               (a)
               (b)

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          3.   SEC Use Only  _______________________________________________

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          4.   Citizenship or Place of Organization
               AMVESCAP PLC: England
               AIM Advisors, Inc.: United States
               AIM Capital Management, Inc.: United States
               AIM Funds Management, Inc.: Canada

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                                    5.      Sole Voting Power 5,046,304: Such
                                            shares are held by the following
                                            entities in the respective amounts
                                            listed: AIM Advisors, Inc. 2,124,138;
                                            AIM Capital Management, Inc. 23,166;
                                            AIM Funds Management, Inc. 2,899,000

Number of Shares           --------------------------------------------------------------------------------------------------
Beneficially Owned
by Each Reporting                   6.      Shared Voting Power       ______-0-______
Person With
                           --------------------------------------------------------------------------------------------------

                                    7.      Sole Dispositive Power 5,046,304: Such
                                            shares are held by the following
                                            entities in the respective amounts
                                            listed: AIM Advisors, Inc. 2,124,138;
                                            AIM Capital Management, Inc. 23,166;
                                            AIM Funds Management, Inc. 2,899,000


                           --------------------------------------------------------------------------------------------------

                                    8.      Shared Dispositive Power     ______-0-______

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          9.   Aggregate Amount Beneficially Owned by Each Reporting Person
               5,046,304

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          10.  Check if the Aggregate Amount in Row (9) Excludes Certain Shares
               (See Instructions) N/A

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          11.  Percent of Class Represented by Amount in Row (9)        10.35%
                                                                        ----
----------------------------------------------------------------------------------------------------------------------------

          12.  Type of Reporting Person (See  Instructions)
               IA, HC. See Items 2 and 3 of this statement.




                                 SCHEDULE 13G


Item 1(a)         Name of Issuer:
                  Open Text Corp.


Item 1(b)         Address of Issuer's Principal Executive Offices:
                  185 Columbia Street West
                     Waterloo, ON  N2L 5Z5
                  Canada

Item 2(a)         Name of Person Filing:
                  AMVESCAP PLC

                  In accordance with Securities and Exchange Commission Release
                  No. 34-39538 (January 12, 1998), this statement on Schedule
                  13G or amendment thereto is being filed by AMVESCAP PLC
                  ("AMVESCAP"), a U.K. entity, on behalf of itself and its
                  subsidiaries listed in Item 4 of the cover of this statement.
                  AMVESCAP through such subsidiaries provides investment
                  management services to institutional and individual investors
                  worldwide.

                  Executive officers and directors of AMVESCAP or its
                  subsidiaries may beneficially own shares of the securities of
                  the issuer to which this statement relates (the "Shares"),
                  and such Shares are not reported in this statement. AMVESCAP
                  and its subsidiaries disclaim beneficial ownership of Shares
                  beneficially owned by any of their executive officers and
                  directors. Each of AMVESCAP's direct and indirect
                  subsidiaries also disclaim beneficial ownership of Shares
                  beneficially owned by AMVESCAP and any other subsidiary.


Item 2(b)         Address of Principal Business Office:
                  30 Finsbury Square
                  London EC2A 1AG
                  England


Item 2(c)         Citizenship:
                  See the response to Item 2(a) of this statement.


Item 2(d)         Title of Class of Securities:
                  Common Stock, $.01 par value per share


Item 2(e)         CUSIP Number:
                  683715106


Item              3 If this statement is filed pursuant to ss240.13d-1(b) or
                  240.13d-2(b) or (c), check whether the person filing is a:

       (e) [x] An investment adviser in accordance with section
               240.13d-1(b)(1)(ii)(E)

       (g) [x] A parent holding company or control person in accordance with
               section 240.13d-1(b)(1)(ii)(G)

                  As noted in Item 2 above, AMVESCAP is making this filing on
                  behalf of its subsidiaries listed herein. Each of these
                  entities is either an investment adviser registered with the
                  United States Securities and Exchange Commission under
                  Section 203 of the Investment Advisers Act of 1940, as
                  amended, or under similar laws of other jurisdictions.
                  AMVESCAP is a holding company.

Item 4            Ownership:

                      Please see responses to Items 5-8 on the cover of this
                      statement, which are incorporated herein by reference.


Item 5            Ownership of Five Percent or Less of a Class:

                      If this statement is being filed to report the fact that
                      as of the date hereof the reporting person has ceased to
                      be the beneficial owner of more than five percent of the
                      class of securities, check the following [ ]

Item 6            Ownership of More than Five Percent on Behalf of Another
                  Person:
                  N/A


Item 7            Identification and Classification of the Subsidiary Which
                  Acquired the Security Being Reported on By the Parent
                  Holding Company:
                  Please see Item 3 of this statement, which is incorporated
                  herein by reference.


Item 8            Identification and Classification of Members of the Group:
                  N/A


Item 9            Notice of Dissolution of a Group:
                  N/A


Item 10           Certification:
                  By signing below I certify that, to the best of my knowledge
                  and belief, the securities referred to above were acquired
                  and are held in the ordinary course of business and were not
                  acquired and are not held for the purpose of or with the
                  effect of changing or influencing the control of the issuer
                  of the securities and were not acquired and are not held in
                  connection with or as a participant in any transaction having
                  that purpose or effect.

                  Signature:
                  After reasonable inquiry and to the best of my knowledge and
                  belief, I certify that the information set forth in this
                  statement is true, complete and correct.


                                                       March 08, 2006
                                              ---------------------------------
                                                           Date

                                              AMVESCAP PLC

                                              By:      /s/  Lisa Brinkley
                                              ---------------------------------


                                                  Lisa Brinkley
                                              Chief Compliance Officer