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                                                                 Exhibit 31.2

                    CHIEF FINANCIAL OFFICER CERTIFICATION

I, Steven Novik, certify that:

1.   I have reviewed this quarterly report on Form 10-Q of The Jones
     Financial Companies, L.L.L.P.

2.   Based on my knowledge, this quarterly report does not contain any
     untrue statement of a material fact or omit to state a material fact
     necessary to make the statements made, in light of the circumstances
     under which such statements were made, not misleading with respect to
     the period covered by this quarterly report.

3.   Based on my knowledge, the financial statements, and other financial
     information included in this quarterly report, fairly present in all
     material respects the financial condition, results of operations and
     cash flows of the Partnership as of, and for, the periods presented in
     this quarterly report.

4.   The Partnership's other certifying officer and I are responsible for
     establishing and maintaining disclosure controls and procedures (as
     defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) for the
     Partnership and have:

     a)   Designed such disclosure controls and procedures, or caused such
          disclosure controls and procedures to be designed under our
          supervision, to ensure that material information relating to the
          Partnership, including its consolidated subsidiaries, is made
          known to us by others within those entities, particularly during
          the period in which this quarterly report is being prepared;

     b)   Evaluated the effectiveness of the Partnership's disclosure
          controls and procedures and presented in this quarterly report our
          conclusions about the effectiveness of the disclosure controls and
          procedures, as of the end of the period covered by this report
          based on such evaluation; and

     c)   Disclosed in this report any change in the Partnership's internal
          control over financial reporting that occurred during the
          Partnership's most recent fiscal quarter that has materially
          affected, or is reasonably likely to materially affect, the
          Partnership's internal control over financial reporting; and

5.   The Partnership's other certifying officer and I have disclosed, based
     on our most recent evaluation of internal control over financial
     reporting, to the Partnership's auditors and the Executive Committee:

     a)   All significant deficiencies and material weaknesses in the design
          or operation of internal controls over financial reporting which
          are reasonably likely to adversely affect the Partnership's
          ability to record, process, summarize, and report financial
          information; and

     b)   Any fraud, whether or not material, that involves management or
          other associates who have a significant role in the Partnership's
          internal control over financial reporting.

                                     /s/ Steven Novik
                                     ---------------------------------------
                                     Chief Financial Officer
                                     The Jones Financial Companies, L.L.L.P.
                                     August 11, 2006

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