<PAGE>

                                                                    Exhibit 10.1

                                                                  EXECUTION COPY

                               JOINDER AGREEMENT

            THIS JOINDER AGREEMENT, dated as of August 14, 2006, is by and among
ASSET ACCEPTANCE, LLC, a Delaware limited liability company, successor by merger
to Financial Credit, LLC, a Delaware limited liability company, and CFC
Financial, LLC, a Delaware limited liability company, CONSUMER CREDIT, LLC, a
Delaware limited liability company, and RX ACQUISITIONS, LLC (f/k/a Med-Fi
Acceptance, LLC), a Delaware limited liability company (individually, an
"Existing Borrower" and, collectively, the "Existing Borrowers"), PREMIUM ASSET
RECOVERY CORPORATION, a Florida corporation (the "New Borrower"), and JPMORGAN
CHASE BANK, N.A., as administrative agent (in such capacity, the "Agent") on
behalf of the Banks (as defined below).

                                   WITNESSETH:

            WHEREAS, the Existing Borrowers, the lenders identified therein (the
"Banks") and the Agent are parties to the Credit Agreement dated as of September
30, 2002 (as amended or modified or joined by any Borrower from time to time,
including any agreement entered into in substitution therefor, the "Credit
Agreement"); and

            WHEREAS, the New Borrower desires to become a party to the Credit
Agreement fully as a "Borrower" thereunder, in the manner hereinafter set forth,
as contemplated by the letter agreement, dated as of April 13, 2006, by and
among the Existing Borrowers, Asset Acceptance Holdings LLC, a Delaware limited
liability company, AAC Investors, Inc., a Virginia corporation, RBR Holding
Corp., a Nevada corporation, Asset Acceptance Capital Corp., a Delaware
corporation, the Agent, Comerica Bank, a Michigan banking corporation, Fifth
Third Bank, Eastern Michigan, a Michigan banking corporation, National City Bank
of the Midwest, a national banking association, and LaSalle Bank Midwest
National Association, a national banking association;

            NOW, THEREFORE, in consideration of the premises, the parties hereto
hereby agree as follows:

            1. The undersigned New Borrower hereby acknowledges and agrees that
it has received, reviewed and approved complete copies of the Credit Agreement,
the Notes, the Facility LC Applications, the Security Documents and all other
agreements, instruments, certificates and other documents furnished by or on
behalf of any of the Borrowers in connection therewith (all of the foregoing, as
amended or modified from time to time, including any agreements or instruments
entered into in substitution therefor, being herein collectively referred to as
the "Loan Documents"), and that it has received and reviewed all other financial
statements, and agreements and documents that it has deemed appropriate and
necessary in order to decide to enter into this Joinder Agreement, and New
Borrower has determined that it is in its interest and to its financial benefit
to enter into the transactions contemplated thereby. New Borrower hereby
unconditionally: (a) joins the Credit Agreement and the other Loan Documents as
a "Borrower" thereunder, (b) agrees to be bound by, and hereby ratifies and
confirms, all covenants, agreements, consents, submissions, appointments,
acknowledgments and other terms and provisions attributable to a "Borrower" in
the Credit Agreement, the Notes and the other Loan Documents; and (c) agrees to
perform all obligations required of it as a "Borrower" by the Credit Agreement,
the Notes and the other Loan Documents.

<PAGE>

            2. The New Borrower hereby represents and warrants that the
representations and warranties with respect to it (as a party joined pursuant to
this Joinder Agreement) contained in, or made or deemed made by it in, the
Credit Agreement and any other Loan Documents are true and correct on and as of
the date hereof. The New Borrower represents and warrants that (a) the
execution, delivery and performance by it of this Joinder Agreement are within
its powers as a corporation, have been duly authorized by all necessary
corporate action, require no consent of, action by or in respect of, or filing
with, any shareholder of New Borrower, any creditor of New Borrower, any
governmental body or any other person or entity, and do not contravene, or
constitute a default under, any provision of applicable law or regulation or of
the articles or certificate of incorporation, bylaws or other charter or
organizational documents of it, or of any agreement, judgment, injunction,
order, decree or other instrument binding upon it or its property; and (b) this
Joinder Agreement has been duly executed and delivered and constitutes a legal,
valid and binding obligation of the New Borrower, enforceable against the New
Borrower in accordance with its terms, except as such enforceability may be
limited by bankruptcy, insolvency, reorganization, moratorium or other similar
laws relating to creditors' rights generally.

            3. The New Borrower agrees to execute and deliver new Notes, such
resolutions and such other documents requested by the Agent as may be necessary
or desirable in order to give effect to, and to aid in the exercise and
enforcement of the rights and remedies of the Banks and the Agent under and
pursuant to, this Joinder Agreement and the Loan Documents.

            4. Each of the Existing Borrowers acknowledges and consents to this
Joinder Agreement, agrees that each of the Credit Agreement and the other Loan
Documents shall remain in full force and effect after giving effect to this
Joinder Agreement, and agrees to execute and deliver new Notes and such other
documents requested by the Agent as may be necessary or desirable in order to
give effect to, and to aid in the exercise and enforcement of the rights and
remedies of the Banks and the Agent under and pursuant to, this Joinder
Agreement and the Loan Documents.

            5. Each of the undersigned Guarantors agrees that its Guaranty
executed in connection with the Credit Agreement shall remain in full force and
effect after giving effect to this Joinder Agreement, including, without
limitation, after including the New Borrower as a "Borrower" under the Credit
Agreement, and such Guaranty shall also guarantee, without limitation, all of
the Obligations of the New Borrower.

            6. Schedule 4.4 attached to this Joinder Agreement is an updated
version of Schedule 4.4 attached to the Credit Agreement (the "Earlier
Schedule"), with respect to which the Borrowers hereby make, as of the date
hereof, the same representations and warranties as set forth in Section 4.4 of
the Credit Agreement with respect to the Earlier Schedule.

            7. This Joinder Agreement shall be governed by, and construed and
interpreted in accordance with, the laws of the State of Michigan.

            8. Capitalized terms used but not defined herein shall have the
meanings ascribed thereto in the Credit Agreement.

            9. This Joinder Agreement may be executed in any number of
counterparts, all of which taken together shall constitute one agreement.

              [The rest of this page is intentionally left blank.]

                                      -2-
<PAGE>

      IN WITNESS WHEREOF, each of the undersigned has caused this Joinder
Agreement to be duly executed and delivered as of the day and year set forth
above.

                                      ASSET ACCEPTANCE, LLC
                                      CONSUMER CREDIT, LLC
                                      RX ACQUISITIONS, LLC

                                      By: /s/ Nathaniel F. Bradley IV
                                         ---------------------------------------
                                              Nathaniel F. Bradley IV
                                              The President of each of them

                                      PREMIUM ASSET RECOVERY
                                        CORPORATION
                                      OUTCOLL SERVICES, INC.

                                      By: /s/ Nathaniel F. Bradley IV
                                         ---------------------------------------
                                              Nathaniel F. Bradley IV
                                              The Chairman of the Board and
                                               CEO of each of them

                                      ASSET ACCEPTANCE CAPITAL CORP.

                                      By: /s/ Nathaniel F. Bradley IV
                                         ---------------------------------------

                                      Print Name:  Nathaniel F. Bradley IV

                                        Its:  President and CEO

                                      AAC INVESTORS, INC.

                                      By: /s/ Nathaniel F. Bradley IV
                                         ---------------------------------------

                                      Print Name:  Nathaniel F. Bradley IV

                                        Its:  President and CEO

                                      RBR HOLDING CORP.

                                      By: /s/ Nathaniel F. Bradley IV
                                         ---------------------------------------

                                      Print Name:  Nathaniel F. Bradley IV

                                        Its:  President and CEO

                                      -3-
<PAGE>

                                      ASSET ACCEPTANCE HOLDINGS LLC
                                      CONSUMER CREDIT, LLC
                                      RX ACQUISITIONS, LLC

                                      By: /s/ Nathaniel F. Bradley IV
                                         ---------------------------------------

                                      Print Name:  Nathaniel F. Bradley IV

                                        Its:  Manager

                                      JPMORGAN CHASE BANK, N.A., successor
                                      by merger to Bank One, NA (Main Office
                                      Chicago), individually and as Agent

                                      By: /s/ Timothy E. Rettberg
                                         ---------------------------------------

                                      Print Name:  Timothy E. Rettberg

                                        Its:  Vice President

                                      -4-
<PAGE>

                                  Schedule 4.4

                                  Subsidiaries

<TABLE>
<CAPTION>
         NAME OF SUBSIDIARY           % OF OWNERSHIP      ENTITY THAT HOLDS OWNERSHIP
-----------------------------------   --------------   ----------------------------------
<S>                                   <C>              <C>
AAC Investors, Inc.                        100%        Asset Acceptance Capital Corp.

RBR Holding Corp.                          100%        Asset Acceptance Capital Corp.

Asset Acceptance Holdings LLC               60%        AAC Investors, Inc.

Asset Acceptance Holdings LLC               40%        RBR Holding Corp.

Asset Acceptance, LLC (successor by        100%        Asset Acceptance Holdings LLC
merger to Financial Credit, LLC and
CFC Financial, LLC)

Consumer Credit, LLC                       100%        Asset Acceptance Holdings LLC

RX Acquisitions, LLC (f/k/a Med-Fi         100%        Asset Acceptance Holdings LLC
Acceptance, LLC)

Premium Asset Recovery Corporation         100%        Asset Acceptance Holdings LLC

Outcoll Services, Inc.                     100%        Premium Asset Recovery Corporation
</TABLE>

                                      -5-