<PAGE>
 
                                                                    Exhibit 3(i)
                  THIRD RESTATED CERTIFICATE OF INCORPORATION

                                      OF

                             METROMAIL CORPORATION


          Metromail Corporation, a Delaware corporation, the original
Certificate of Incorporation of which was filed with the Secretary of State of
the State of Delaware on November 29, 1979, HEREBY CERTIFIES that this Third
Restated Certificate of Incorporation restating, integrating and amending its
Restated Certificate of Incorporation was duly proposed by the Board of
Directors and unanimously adopted by its stockholders in accordance with
Sections 228, 242 and 245 of the Delaware General Corporation Law.

          FIRST:  The name of the Corporation is Metromail Corporation.

          SECOND:  The address of the Corporation's registered office in the
State of Delaware is Corporation Trust Center, 1209 Orange Street, in the City
of Wilmington, County of New Castle.  The name of the Corporation's registered
agent at such address is The Corporation Trust Company.

          THIRD:  The purpose of the Corporation is to engage in any lawful act
or activity for which corporations may be organized under the General
Corporation Law of Delaware (the "DGCL").

          FOURTH:  A.  The total number of shares of all classes of capital
stock which the Corporation shall have the authority to issue is 75,000,000
shares of Common Stock, each with a par value of $.01 per share, and 20,000,000
shares of Preferred Stock, each with a par value of $.01 per share.  At the time
at which this Third Restated Certificate of Incorporation is filed with the
Secretary of State of the State of Delaware (the "Filing Time"), each share of
Common Stock, par value $.40 per share, of the Corporation that shall be issued
and outstanding or held for any purpose in the treasury of the Corporation
immediately prior thereto shall be reclassified by changing such share into
8,600 shares of Common Stock, par value $.01 per share.

          B.  The Board of Directors is expressly authorized to provide for the
issuance of all or any shares of the Preferred Stock in one or more classes or
series, and to fix for each such class or series such voting powers, full or
limited, or no voting powers, and such distinctive designations, preferences and
relative, participating, optional or other special rights and such
qualifications, limitations or restrictions thereof, as shall be stated and
expressed in the resolution or resolutions adopted by the Board of Directors
providing for the issuance of such class or series and as may be permitted by
the DGCL, including, without limitation, the authority to provide that any such
class or series may be (i) subject to redemption at such time or times and at
such
<PAGE>
 
price or prices; (ii) entitled to receive dividends (which may be
cumulative or non-cumulative) at such rates, on such conditions, at such times,
and payable in preference to, or in such relation to, the dividends payable on
any other class or classes or any other series; (iii) entitled to such rights
upon the dissolution of, or upon any distribution of the assets of, the
Corporation; or (iv) convertible into, or exchangeable for, shares of any other
class or classes of stock, or of any other series of the same or any other class
or classes of stock, or other securities or property, of the Corporation at such
price or prices or at such rates of exchange and with such adjustments; all as
may be stated in such resolution or resolutions.

          FIFTH:  A.  The business and affairs of the Corporation shall be
managed by or under the direction of a Board of Directors consisting of not less
than one nor more than fifteen directors, the exact number of directors to be
determined from time to time by resolution adopted by affirmative vote of a
majority of the entire Board of Directors.  The directors shall be divided into
three classes, designated Class I, Class II and Class III.  Each class shall
consist, as nearly as may be possible, of one-third of the total number of
directors constituting the entire Board of Directors.  Class I directors shall
be elected initially for a one-year term, Class II directors initially for a
two-year term and Class III directors initially for a three-year term.  At each
succeeding annual meeting of stockholders beginning in 1997, successors to the
class of directors whose term expires at that annual meeting shall be elected
for a three-year term.  If the number of directors is changed, any increase or
decrease shall be apportioned among the classes so as to maintain the number of
directors in each class as nearly equal as possible, and any additional director
of any class elected to fill a vacancy resulting from an increase in such class
shall hold office for a term that shall coincide with the remaining term of that
class, but in no case will a decrease in the number of directors shorten the
term of any incumbent director.  A director shall hold office until the annual
meeting for the year in which his term expires and until his successor shall be
elected and shall qualify, subject, however, to prior death, resignation,
retirement, disqualification or removal from office.  Any vacancy on the Board
of Directors may be filled only by a majority of the directors then in office,
even if less than a quorum, or a sole remaining director.

          Any director elected to fill a vacancy not resulting from an increase
in the number of directors shall have the same remaining term as that of his
predecessor.

          B.  A director may be removed only by the holders of a majority of
shares of Common Stock then entitled to vote at an election of directors and
only for cause.

          SIXTH:  A director of the Corporation shall not be personally liable
to the Corporation or its stockholders for monetary damages for breach of
fiduciary duty as a director, except for liability (i) for any breach of the
director's duty of loyalty to the Corporation or its stockholders, (ii) for acts
or omissions not in good faith or which involve intentional misconduct or a
knowing violation of law, (iii) under Section 174 of the DGCL, or (iv) for any
transaction from which the director derived an improper personal benefit.  If
the DGCL is amended to authorize corporate action further eliminating or
limiting the personal liability of directors, then the liability of a director
of the Corporation shall be eliminated or limited to the fullest extent
permitted by the DGCL, as so amended.  Any repeal or modification of this
Article SIXTH by 
<PAGE>
 
the stockholders of the Corporation shall not adversely affect any right or
protection of a director of the Corporation existing at the time of such repeal
or modification.

          SEVENTH:  A.  The Corporation shall indemnify to the fullest extent
permitted under and in accordance with the laws of the State of Delaware any
person who was or is a party or is threatened to be made a party to any
threatened, pending or completed action, suit or proceeding, whether civil,
criminal, administrative or investigative by reason of the fact that he is or
was a director, officer, employee or agent of the Corporation, or is or was
serving at the request of the Corporation as a director, officer, trustee,
employee or agent of or in any other capacity with another corporation,
partnership, joint venture, trust or other enterprise, against expenses
(including attorneys' fees), judgments, fines and amounts paid in settlement
actually and reasonably incurred by him in connection with such action, suit or
proceeding if he acted in good faith and in a manner he reasonably believed to
be in or not opposed to the best interests of the Corporation, and, with respect
to any criminal action or proceeding, had no reasonable cause to believe his
conduct was unlawful.

          B.  Expenses incurred in defending a civil or criminal action, suit or
proceeding shall (in the case of any action, suit or proceeding against a
director of the Corporation) or may (in the case of any action, suit or
proceeding against an officer, trustee, employee or agent of the Corporation) be
paid by the Corporation in advance of the final disposition of such action, suit
or proceeding as authorized by the Board of Directors upon receipt of an
undertaking by or on behalf of the indemnified person to repay such amount if it
shall ultimately be determined that he is not entitled to be indemnified by the
Corporation as authorized in this Article SEVENTH.

          C.  The indemnification and other rights set forth in this Article
SEVENTH shall not be exclusive of any provisions with respect thereto in the By-
laws or any other contract or agreement between the Corporation and any officer,
director, employee or agent of the Corporation.

          D.  Neither the amendment nor repeal of Section A, B or C of this
Article SEVENTH nor the adoption of any provision of this Third Restated
Certificate of Incorporation inconsistent with Section A, B or C of this Article
SEVENTH shall eliminate or reduce the effect of Sections A, B and C of this
Article SEVENTH in respect of any matter occurring prior to such amendment,
repeal or adoption of an inconsistent provision or in respect of any cause of
action, suit or claim relating to any such matter which would have given rise to
a right of indemnification or right to receive expenses pursuant to Section A, B
or C of this Article SEVENTH if such provision had not been so amended or
repealed or if a provision inconsistent therewith had not been so adopted.

          EIGHTH:  Any action required or permitted to be taken by the
stockholders of the Corporation may be effected only at a duly called annual or
special meeting of such holders and may not be effected by a consent in writing
by such holders in lieu of such a meeting.

          NINTH: In furtherance and not in limitation of the powers conferred by
statute, the Board of Directors is expressly authorized to make, alter or repeal
the By-laws of the 
<PAGE>
 
Corporation, subject to any specific limitation or such power contained in any
By-laws adopted by the stockholders of the Corporation and subject to the
provisions in this Third Restated Certificate of Incorporation. Elections of
directors need not be by written ballot unless the By-laws of the Corporation so
provide.

          TENTH:  In accordance with Section 203(b)(3) of the DGCL, the
Corporation expressly elects not to be governed by Section 203 of the DGCL;
provided, that this Article TENTH shall not be effective until 12 months after
the Filing Time and in no event shall this Article TENTH apply to any business
combination between the Corporation and any person who became an interested
stockholder of the Corporation prior to the Filing Time.

          ELEVENTH:  The Corporation reserves the right to amend, alter, change
or repeal any provision contained in this Third Restated Certificate of
Incorporation, in the manner now or hereafter prescribed by statute, and all
rights conferred upon the stockholders herein are granted subject to this
reservation.

          IN WITNESS WHEREOF, Metromail Corporation has caused this Third
Restated Certificate of Incorporation to be signed on this 29th day of February,
1996 in its name by a duly authorized officer.



                                       METROMAIL CORPORATION



                                       By:  /s/ Barton L. Faber
                                            -------------------------
                                                Barton L. Faber
                                                Chairman
<PAGE>
 
                             METROMAIL CORPORATION

                  CERTIFICATE OF DESIGNATION, PREFERENCES AND
           RIGHTS OF JUNIOR PARTICIPATING PREFERRED STOCK, SERIES A
                                        

                Pursuant to Section 151 of the Corporation Law
                           of the State of Delaware


          I, Thomas J. Quarles, the Senior Vice President and General Counsel of
Metromail Corporation, a corporation organized and existing under the General
Corporation Law of the State of Delaware, in accordance with the provisions of
Section 151 thereof, DO HEREBY CERTIFY:

          That pursuant to the authority conferred upon the Board of Directors
by the Third Restated Certificate of Incorporation of the Corporation, the Board
of Directors on February 24, 1997, adopted the following resolution creating a
series of 75,000 shares of Preferred Stock designated as Junior Participating
Preferred Stock, Series A:

          RESOLVED, that pursuant to the authority vested in the Board by the
Third Restated Certificate of Incorporation of the Corporation and out of the
Preferred Stock authorized therein, the Board hereby authorizes that a series of
Preferred Stock of the Corporation be, and it hereby is, created and that the
designation and amount thereof and the voting powers, preferences and relative,
participating, optional and other special rights of the shares of such series,
and the qualifications, limitations or restrictions thereof are as follows:

          Section 1.  Designation and Amount.  The shares of such series shall
be designated as "Junior Participating Preferred Stock, Series A," par value
$.01 per share (the "Series A Preferred Stock") and the number of shares
constituting such series shall be 75,000.

          Section 2.  Dividends and Distributions.
          
               (A)  Subject to the prior and superior rights of the holders of
          any shares of any series of Preferred Stock ranking prior and superior
          to the shares of Series A Preferred Stock with respect to dividends,
          the holders of shares of Series A Preferred Stock, in preference to
          the holders of Common Stock and of any other junior stock, shall be
          entitled to receive, when, as and if declared by the Board of
          Directors out of funds legally available for the purpose, quarterly
          dividends payable in cash on the fifteenth day of March, June,
          September and December in each year (each such date, a "Quarterly
          Dividend Payment Date"), commencing 
<PAGE>
 
          on the first Quarterly Dividend Payment Date after the first issuance
          of a share or fraction of a share of Series A Preferred Stock, in an
          amount per share (rounded to the nearest cent) equal to the greater of
          (a) $25.00 or (b) the Adjustment Number (as defined below) times the
          aggregate per share amount of all cash dividends, and the Adjustment
          Number times the aggregate per share amount (payable in kind) of all
          non-cash dividends or other distributions other than a dividend
          payable in shares of Common Stock or a subdivision of the outstanding
          shares of Common Stock (by reclassification or otherwise), declared on
          the Common Stock since the immediately preceding Quarterly Dividend
          Payment Date or, with respect to the first Quarterly Dividend Payment
          Date, since the first issuance of any share or fraction of a share of
          Series A Preferred Stock. The "Adjustment Number" shall initially be
          1000. In the event the Corporation shall at any time after February
          24, 1997 (i) declare or pay any dividend on Common Stock payable in
          shares of Common Stock, (ii) subdivide the outstanding Common Stock
          into a greater number of shares or (iii) combine the outstanding
          Common Stock into a smaller number of shares, then in each such case
          the Adjustment Number in effect immediately prior to such event shall
          be adjusted by multiplying such Adjustment Number by a fraction the
          numerator of which is the number of shares of Common Stock outstanding
          immediately after such event and the denominator of which is the
          number of shares of Common Stock that were outstanding immediately
          prior to such event.

               (B)  The Corporation shall declare a dividend or distribution on
          the Series A Preferred Stock as provided in paragraph (A) of this
          Section immediately after it declares a dividend or distribution on
          the Common Stock (other than a dividend payable in shares of Common
          Stock); provided that, in the event no dividend or distribution shall
          have been declared on the Common Stock during the period between any
          Quarterly Dividend Payment Date and the next subsequent Quarterly
          Dividend Payment Date, a dividend of $25.00 per share on the Series A
          Preferred Stock shall nevertheless be payable on such subsequent
          Quarterly Dividend Payment Date.

               (C)  Dividends shall begin to accrue and be cumulative on
          outstanding shares of Series A Preferred Stock from the Quarterly
          Dividend Payment Date next preceding the date of issue of such shares
          of Series A Preferred Stock, unless the date of issue of such shares
          is prior to the record date for the first Quarterly Dividend Payment
          Date, in which case dividends on such shares shall begin to accrue
          from the date of issue of such shares, or unless the date of issue is
          a Quarterly Dividend Payment Date or is a date after the record date
          for the determination of holders of shares of Series A Preferred Stock
          entitled to receive a quarterly dividend and before such Quarterly
          Dividend Payment Date, in either of which events such dividends shall
          begin to accrue and be cumulative from such Quarterly Dividend Payment
          Date.  Accrued but unpaid dividends shall not bear interest.
          Dividends paid on the shares of Series A Preferred Stock in an amount
          less than the total amount of such dividends at the time accrued and
          payable on 
<PAGE>
 
          such shares shall be allocated pro rata on a share-by-share basis
          among all such shares at the time outstanding.  The Board of Directors
          may fix a record date for the determination of holders of shares of
          Series A Preferred Stock entitled to receive payment of a dividend or
          distribution declared thereon, which record date shall be no more than
          30 days prior to the date fixed for the payment thereof.

          Section 3.  Voting Rights.  The holders of shares of Series A
Preferred Stock shall have the following voting rights:

               (A) Each share of Series A Preferred Stock shall entitle the
          holder thereof to a number of votes equal to the Adjustment Number (as
          adjusted from time to time pursuant to Section 2(A) hereof) on all
          matters submitted to a vote of the stockholders of the Corporation.

               (B)  Except as otherwise provided herein, in the Certificate of
          Incorporation or bylaws, the holders of shares of Series A Preferred
          Stock and the holders of shares of Common Stock shall vote together as
          one class on all matters submitted to a vote of stockholders of  the
          Corporation.

               (C)  (i)  If at any time dividends on any Series A Preferred
          Stock shall be in arrears in an amount equal to six quarterly
          dividends thereon, the occurrence of such contingency shall mark the
          beginning of a period (a "default period") that shall extend until
          such time when all accrued and unpaid dividends for all previous
          quarterly dividend periods and for the current quarterly period on all
          shares of Series A Preferred Stock then outstanding shall have been
          declared and paid or set apart for payment. During each default
          period, (1) the number of Directors shall be increased by two,
          effective as of the time of election of such Directors as herein
          provided, and (2) the holders of Series A Preferred Stock and the
          holders of other Preferred Stock upon which these or like voting
          rights have been conferred and are exercisable (the "Voting Preferred
          Stock") with dividends in arrears equal to six quarterly dividends
          thereon, voting as a class, irrespective of series, shall have the
          right to elect such two Directors.

                  (ii)  During any default period, such voting right of the
          holders of Series A Preferred Stock may be exercised initially at a
          special meeting called pursuant to subparagraph (iii) of this Section
          3(C) or at any annual meeting of stockholders, and thereafter at
          annual meetings of stockholders, provided that such voting right shall
          not be exercised unless the holders of at least one-third in number of
          the shares of Voting Preferred Stock outstanding shall be present in
          person or by proxy.  The absence of a quorum of the holders of Common
          Stock shall not affect the exercise by the holders of Voting Preferred
          Stock of such voting right.

                  (iii)  Unless the holders of Voting Preferred Stock shall,
          during an existing default period, have previously exercised their
          right to elect Directors, the 
<PAGE>
 
          Board of Directors may order, or any stockholder or stockholders
          owning in the aggregate not less than 10% of the total number of
          shares of Voting Preferred Stock outstanding, irrespective of series,
          may request, the calling of a special meeting of the holders of Voting
          Preferred Stock, which meeting shall thereupon be called by the
          Chairman of the Board, the Chief Executive Officer, the President, a
          Vice President or the Secretary of the Corporation. Notice of such
          meeting and of any annual meeting at which holders of Voting Preferred
          Stock are entitled to vote pursuant to this paragraph (C)(iii) shall
          be given to each holder of record of Voting Preferred Stock by mailing
          a copy of such notice to him at his last address as the same appears
          on the books of the Corporation. Such meeting shall be called for a
          time not earlier than 10 days and not later than 60 days after such
          order or request or, in default of the calling of such meeting within
          60 days after such order or request, such meeting may be called on
          similar notice by any stockholder or stockholders owning in the
          aggregate not less than 10% of the total number of shares of Voting
          Preferred Stock outstanding. Notwithstanding the provisions of this
          paragraph (C)(iii), no such special meeting shall be called during the
          period within 60 days immediately preceding the date fixed for the
          next annual meeting of the stockholders.

                  (iv)  In any default period, after the holders of Voting
          Preferred Stock shall have exercised their right to elect Directors
          voting as a class, (x) the Directors so elected by the holders of
          Voting Preferred Stock shall continue in office until their successors
          shall have been elected by such holders or until the expiration of the
          default period, and (y) any vacancy in the Board of Directors may be
          filled by vote of a majority of the remaining Directors theretofore
          elected by the holders of the class or classes of stock which elected
          the Director whose office shall have become vacant.  References in
          this paragraph (C) to Directors elected by the holders of a particular
          class or classes of stock shall include Directors elected by such
          Directors to fill vacancies as provided in clause (y) of the foregoing
          sentence.

                   (v)  Immediately upon the expiration of a default period, (x)
          the right of the holders of Voting Preferred Stock as a class to elect
          Directors shall cease, (y) the term of any Directors elected by the
          holders of Voting Preferred Stock as a class shall terminate and (z)
          the number of Directors shall be such number as may be provided for in
          the Certificate of Incorporation or bylaws irrespective of any
          increase made pursuant to the provisions of paragraph (C) of this
          Section 3 (such number being subject, however, to change thereafter in
          any manner provided by law or in the Certificate of Incorporation or
          bylaws).  Any vacancies in the Board of Directors effected by the
          provisions of clauses (y) and (z) in the preceding sentence may be
          filled by a majority of the remaining Directors.
<PAGE>
 
               (D)  Except as set forth herein, holders of Series A Preferred
          Stock shall have no special voting rights and their consent shall not
          be required (except to the extent they are entitled to vote with
          holders of Common Stock as set forth herein) for taking any corporate
          action.

          Section 4.  Certain Restrictions.

               (A)  Whenever quarterly dividends or other dividends or
          distributions payable on the Series A Preferred Stock as provided in
          Section 2 are in arrears, thereafter and until all accrued and unpaid
          dividends and distributions, whether or not declared, on shares of
          Series A Preferred Stock outstanding shall have been paid in full, the
          Corporation shall not:

                  (i)  declare or pay dividends on, or make any other
          distributions on, any shares of stock ranking junior (either as to
          dividends or upon liquidation, dissolution or winding up) to the
          Series A Preferred Stock;

                  (ii) declare or pay dividends on or make any other
          distributions on any shares of stock ranking on a parity (either as to
          dividends or upon liquidation, dissolution or winding up) with the
          Series A Preferred Stock, except dividends paid ratably on the Series
          A Preferred Stock and all such parity stock on which dividends are
          payable or in arrears in proportion to the total amounts to which the
          holders of all such shares are then entitled;

                   (iii) redeem or purchase or otherwise acquire for
          consideration shares of any stock ranking junior (either as to
          dividends or upon liquidation, dissolution or winding up) to the
          Series A Preferred Stock, provided that the Corporation may at any
          time redeem, purchase or otherwise acquire shares of any such junior
          stock in exchange for shares of any stock of the Corporation ranking
          junior (either as to dividends or upon dissolution, liquidation or
          winding up) to the Series A Preferred Stock; or

                  (iv)  purchase or otherwise acquire for consideration any
          shares of Series A Preferred Stock, or any shares of stock ranking on
          a parity with the Series A Preferred Stock, except in accordance with
          a purchase offer made in writing or by publication (as determined by
          the Board of Directors) to all holders of such shares upon such terms
          as the Board of Directors, after consideration of the respective
          annual dividend rates and other relative rights and preferences of the
          respective series and classes, shall determine in good faith will
          result in fair and equitable treatment among the respective series or
          classes.

               (B)  The Corporation shall not permit any subsidiary of the
          Corporation to purchase or otherwise acquire for consideration any
          shares of stock of the Corporation unless the Corporation could, under
          paragraph (A) of this Section 4, purchase or otherwise acquire such
          shares at such time and in such manner.
<PAGE>
 
          Section 5.  Reacquired Shares.  Any shares of Series A Preferred Stock
purchased or otherwise acquired by the Corporation in any manner whatsoever
shall be retired and cancelled promptly after the acquisition thereof.  All such
shares shall upon their cancellation become authorized but unissued shares of
Preferred Stock and may be reissued as part of a new series of Preferred Stock
to be created by resolution or resolutions of the Board of Directors, subject to
the conditions and restrictions on issuance set forth herein.

          Section 6.  Liquidation, Dissolution or Winding Up.  Upon any
liquidation, dissolution or winding up of the Corporation, no distribution shall
be made (A) to the holders of shares of stock ranking junior (either as to
dividends or upon liquidation, dissolution or winding up) to the Series A
Preferred Stock unless, prior thereto, the holders of shares of Series A
Preferred Stock shall have received the greater of (i) $100 per share, plus an
amount equal to accrued and unpaid dividends and distributions thereon, whether
or not declared, to the date of such payment, and (ii) an aggregate amount per
share, equal to the Adjustment Number (as adjusted from time to time pursuant to
Section 2(A) hereof) times the aggregate amount to be distributed per share to
holders of Common Stock, or (B) to the holders of stock ranking on a parity
(either as to dividends or upon liquidation, dissolution or winding up) with the
Series A Preferred Stock, except distributions made ratably on the Series A
Preferred Stock and all other such parity stock in proportion to the total
amounts to which the holders of all such shares are entitled upon such
liquidation, dissolution or winding up.

          Section 7.  Consolidation, Merger, etc.  In case the Corporation shall
enter into any consolidation, merger, combination or other transaction in which
the shares of Common Stock are exchanged for or changed into other stock or
securities, cash and/or any other property, then in any such case the shares of
Series A Preferred Stock then outstanding shall at the same time be similarly
exchanged or changed in an amount per share equal to the Adjustment Number (as
adjusted from time to time pursuant to Section 2(A) hereof) times the aggregate
amount of stock, securities, cash and/or any other property (payable in kind),
as the case may be, into which or for which each share of Common Stock is
changed or exchanged.

          Section 8.  No Redemption.  The shares of Series A Preferred Stock
shall not be redeemable.

          Section 9.  Amendment.  The Certificate of Incorporation of the
Corporation shall not be amended in any manner which would materially alter or
change the powers, preferences or special rights of the Series A Preferred Stock
so as to affect them adversely without the affirmative vote of the holders of
two-thirds of the outstanding shares of Series A Preferred Stock, voting
together as a single class.
<PAGE>
 
IN WITNESS WHEREOF, I have executed and subscribed this Certificate and do
affirm the foregoing as true under the penalties of perjury this 24th day of
February, 1997.



                                /s/ Thomas J. Quarles
                                ------------------------------------------------
                                Name: Thomas J. Quarles
                                Title: Senior Vice President and General Counsel