<ARTICLE> 5
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM ONESOURCE
INFORMATION SERVICES, INC.'S CONSOLIDATED BALANCE SHEET (UNAUDITED) FOR
SEPTEMBER 30, 1999 AND CONSOLIDATED STATEMENT OF OPERATIONS FOR THE NINE MONTHS
ENDED SEPTEMBER 30, 1999 AND IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH
FINANCIAL STATEMENTS.
</LEGEND>
<MULTIPLIER> 1,000
<CURRENCY> U.S. DOLLARS

                             
<PERIOD-TYPE>                   9-MOS
<FISCAL-YEAR-END>                          DEC-31-1998
<PERIOD-START>                             JAN-01-1999
<PERIOD-END>                               SEP-30-1999
<EXCHANGE-RATE>                                      1
<CASH>                                          14,665
<SECURITIES>                                         0
<RECEIVABLES>                                    6,500
<ALLOWANCES>                                       288
<INVENTORY>                                          0
<CURRENT-ASSETS>                                34,678
<PP&E>                                           7,683
<DEPRECIATION>                                   4,934
<TOTAL-ASSETS>                                  38,460
<CURRENT-LIABILITIES>                           24,322
<BONDS>                                              0
<PREFERRED-MANDATORY>                                0
<PREFERRED>                                          0
<COMMON>                                           100
<OTHER-SE>                                      13,979
<TOTAL-LIABILITY-AND-EQUITY>                    38,460
<SALES>                                         25,241
<TOTAL-REVENUES>                                25,241
<CGS>                                           10,805
<TOTAL-COSTS>                                   10,805
<OTHER-EXPENSES>                                19,129
<LOSS-PROVISION>                                     0
<INTEREST-EXPENSE>                                  99
<INCOME-PRETAX>                                (3,292)
<INCOME-TAX>                                         0
<INCOME-CONTINUING>                            (3,292)
<DISCONTINUED>                                       0
<EXTRAORDINARY>                                      0
<CHANGES>                                            0
<NET-INCOME>                                   (3,292)
<EPS-BASIC>                                     (0.39)
<EPS-DILUTED>                                   (0.39)