ADDENDUM NUMBER SEVEN TO LEASE

THIS  ADDENDUM  NUMBER  SEVEN TO LEASE is made and entered  into this 1st day of
March 1990, by and between  S.R.P.  Limited  Partnership,  (Landlord)  and Fair,
Isaac and Company, Incorporated (Tenant), and shall constitute a modification of
that Lease  between the  parties  dated  October  20,  1983 (Base  Lease) and as
amended on May 1, 1984, September 21, 1984, February 8, 1985, September 3, 1985,
November 21,  1985,  and October 1, 1986,  relating to the premises  occupied by
Tenant in the building  commonly known as 120 North Redwood  Drive,  San Rafael,
California 94903. This action  constitutes both the extension of the term of the
Lease, and the expansion of Tenant into future available space.

The parties hereto agree that:

1. The leased  premises  shall be increased by 3,488  rentable  square feet,  to
include the space commonly known as Suite 350, effective upon ninety days notice
to  Tenant,  for  possession  no earlier  than July 1,  1990,  and no later than
October 1, 1990.

2. Tenant agrees to lease Suite 375, comprised of 2,472 rentable square feet, at
such time as that space is first  available  for lease,  upon the same terms and
conditions as is then existing under the Lease.

3. The  expiration  date of the Lease for both  existing  and  future  expansion
Tenant space shall be changed to December 31, 2001.

4. The Option to Renew,  contained  in  Paragraph  32 of the Base Lease shall be
changed such that the first option period,  if exercised,  shall now commence on
January  1,  2002.  The  Option to Renew is only  available  on all of the space
contained in the Lease, at the time of option exercise.  This Option is personal
to Tenant and is not available to sublessee or sublessees of Tenant's leasehold.

5. The  combination of Basic Rent and Additional Rent for the period of March 1,
1990,  to December 31, 1990,  shall be computed at the monthly rate of $1.90 per
rentable square foot, prior to a monthly credit in the amount of $2,150 for west
wing utility  expense and first floor west wing janitorial  expense.  Therefore,
until  expansion space is included in the leased  premises,  the monthly rent on
the existing 36,554 rentable square feet shall be $67,303.

6. Additional Rent as defined and administered by Paragraph 7 of the Lease shall
be unchanged except that Base Year shall now refer to and mean the calendar year
1990.  During the revised Base Year 1990, the portion of total rent attributable
to  Additional  Rent shall be equal to the actual Tenant  Proportional  Share as
retroactively determined at the end of the Base Year.

     Example: Considering only Tenant's present space, if at the end of 1990, it
     is determined that Tenant's  proportional  share of 1990 operating expenses
     on a monthly  basis equaled  $16,500,  then that amount shall be subtracted
     from the $67,303  total monthly  rent,

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                                                                   Exhibit 10.11




     therefore  providing a remainder of $50,803 as the Base Year Basic  Monthly
     Rent.

     Then,  during 1991, the $16,500 Monthly  Additional Rent will be used as an
     estimate of monthly  operating  expenses,  with an adjustment at the end of
     the year to reflect actual operating expenses,  creating a resultant rebate
     or  recapture as is then  determined  to be  appropriate,  per the terms of
     Paragraph 7 of the Lease.

7.  Paragraph 6 "Adjusted  Basic Rent," of the Base Lease shall be modified such
that the  combination of increases in rent under  Paragraphs 6 and 7 shall in no
event exceed a 7.5% increase over the combined  rental under said Paragraphs for
the immediately preceding lease year.

8.  Paragraph 9 "Use," of the Base Lease  shall be  modified  such that "use" is
defined as "general office purposes," instead of "general office purposes of the
Fair, Isaac Companies."

9. Paragraph 24  "Reconstruction," of the Base Lease shall be modified such that
if the time period required to complete  restoration of the Premises or Building
is greater than twelve  months from the date of the damage,  either  Landlord or
Tenant shall have the right to terminate the Lease within thirty (30) days after
the date of the determination  that such  reconstruction  will require more than
twelve months.  Landlord will make such  determination and notify Tenant of such
determination within sixty (60) days of the event of damage.

10. Paragraph 13.b. of the Base Lease is modified so that Landlord's obligations
with  respect  to repair  and  maintenance  of the  structural  portions  of the
building shall explicitly  include any modifications  required of the structural
portions of the building under then current building and fire codes.

11. All other terms and conditions of the Base Lease shall remain unchanged.

Landlord: S.R.P. Limited                   Tenant: Fair, Isaac and Company, Inc.
          Partnership



By: _________________________________      By: _________________________________

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