Document:

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                                                                   Exhibit 10.15

                                 FIRST AMENDMENT
                                       TO
                           SECOND AMENDED AND RESTATED
                           LOAN AND SECUTITY AGREEMENT

This First Amendment to the Second Amended and Restated Loan and Security
Agreement (the "Amendment") is entered into as of July 2, 2002, by and between
COMERICA BANK - CALIFORNIA ("Bank") and INPHONIC, INC. and SIMIPC ACQUISITION
CORP. ("Borrower").

                                    RECITALS

          Borrower and Bank are parties to that certain Second Amended and
Restated Loan and Security Agreement dated as of March 1, 2002, (as amended from
time to time, together with any related agreements, the "Agreement").
Hereinafter, all indebtedness owing by Borrower to Bank shall be referred to as
the "Indebtedness." The parties desire to amend the Agreement in accordance with
the terms of this Amendment. This Amendment shall be effective as of March 31,
2002.

          NOW, THEREFORE, for good and valuable consideration, the receipt and
sufficiency of which are hereby acknowledged, the parties agree as follows:

I.        Incorporation by Reference. The Recitals and the documents referred to
          therein are incorporated herein by their reference. Except as
          otherwise noted, the terms not defined herein shall have the meaning
          set forth in the Agreement.

II.       Amendment to the Agreement. Subject to the satisfaction of the
          conditions precedent as set forth in Article III hereof, the Agreement
          is hereby amended as set forth below.

          A.      Section 6.2(b) of the Agreement is hereby extended from "June
                  30, 2002" to "July 31, 2002."

          B.      Section 6.7(a) of the Agreement is hereby deleted in its
                  entirety and replaced with the following financial covenant:

                  Minimum Cash. At all times the Borrower is required to
                  maintain unrestricted cash balances in the Bank equal to at
                  least 2 times its outstandings (including non-cash secured
                  Letters of Credit) under Bank facilities.

          C.      Section 6.7(b) of the Agreement is hereby deleted in its
                  entirety.

III.      Legal Effect.

          A.      The Agreement is hereby amended wherever necessary to reflect
                  the changes described above.

          B.      Borrower agrees that it has no defenses against the
                  obligations to pay any amounts under the Indebtedness.

          C.      Borrower understands and agrees that in modifying the existing
                  Indebtedness, Bank is relying upon Borrower's representations,
                  warranties, and agreements, as set forth in the Agreement.
                  Except as expressly modified pursuant to this Amendment, the
                  terms of the Agreement remain unchanged, and in full force and
                  effect. Bank's agreement to modifications to the existing
                  indebtedness pursuant to this Amendment in no way shall
                  obligate Bank to make any future modifications to the
                  Indebtedness. Nothing in this Amendment shall constitute a
                  satisfaction of the Indebtedness. It is the intention of Bank
                  and Borrower to retain as liable parties, all makers

AMENDMENT
PAGE 1 of 2

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                  and endorsers of Agreement, unless the party is expressly
                  released by Bank in writing. No maker, endorser, or guarantor
                  will be released by virtue of this Amendment. The terms of
                  this paragraph apply not only to this Amendment, but also to
                  all subsequent loan modification requests.

          D.      This Amendment may be executed in two or more counterparts,
                  each of which shall be deemed an original, but all of which
                  together shall constitute one instrument.

          E.      This is an integrated Amendment and supersedes all prior
                  negotiations and agreements regarding the subject matter
                  hereof. All modifications hereto must be in writing and signed
                  by the parties.

IV.       Conditions Precedent. Except as specifically set forth in this
          Amendment, all of the terms and conditions of the Agreement remain in
          full force and effect. The effectiveness of this Agreement is
          conditioned upon receipt by Bank of this Amendment, and any other
          documents which Bank may require to carry out the terms hereof,
          including but not limited to the following:

          A.      This Amendment, duly executed by Borrower;

          B.      A legal fee from the Borrower in the amount of $250; and

          C.      Such other documents, and completion of such other matters, as
                  Bank may reasonably deem necessary or appropriate.

IN WITNESS WHEREOF, the undersigned have executed this Amendment as of the first
date above written.

                                         INPHONIC, INC.

                                         By: /s/ David A. Steinberg
                                             _____________________________

                                         Title:___________________________

                                         SIMIPC ACQUISITION CORP.

                                         By: /s/ David A. Steinberg
                                             _____________________________

                                         Title:___________________________

                                         COMMERICA BANK - CALIFORNIA

                                         By: /s/ Bradley Steel
                                             _____________________________

                                         Title:___________________________

AMENDMENT
PAGE 2 of 2<PAGE>

                                                                   Exhibit 10.16

                 SECOND AMENDMENT TO SECOND AMENDED AND RESTATED
                           LOAN AND SECURITY AGREEMENT

         This Second Amendment to Second Amended and Restated Loan and Security
Agreement ("Amendment") is made and entered into as of September _, 2002, by and
among InPhonic, Inc. ("InPhonic"), SimIpc Acquisition Corp. ("SimIpc" and
together with Inphonic, the "Borrowers"), and Comerica Bank - California,
("Bank").

                                    Recitals

         A.       Borrowers and Bank have entered into that certain Second
Amended and Restated Loan and Security Agreement dated as of March 1, 2002, as
amended by that certain First Amendment to Second Amended and Restated Loan and
Security Agreement dated as of July 2, 2002 (as the same may from time to time
be modified, amended, supplemented, restated or superseded, the "Loan
Agreement") pursuant to which Bank has agreed to extend and make available to
Borrower certain advances of money.

         B.       Borrowers desire that Bank amend the Loan Agreement upon the
terms and conditions more folly set forth herein.

         C.       Subject to the representations and warranties of Borrowers
herein and upon the terms and conditions set forth in this Amendment, Bank is
willing to so amend the Loan Agreement.

         D.       This Amendment, the Loan Agreement and the other Loan
Documents (as defined in the Loan Agreement), together with all other documents
entered into or delivered pursuant to any of the foregoing, in each case as
originally executed or as the same may from time to time be modified, amended,
supplemented, restated or superseded are hereinafter collectively referred to as
the "Loan Documents."

                                    Agreement

         Now, Therefore, in consideration of the foregoing recitals and the
mutual covenants herein set forth and for other good and valuable consideration,
the receipt and sufficiency of which are hereby acknowledged, and intending to
be legally bound, Borrowers and Bank hereby agree to amend the Loan Agreement as
follows:

                  1.       Definitions.  Unless otherwise defined herein, all
terms defined in the Loan Agreement have the same meaning when used herein.

                  2.       Amendments to Loan Agreement.

                           2.1.     Section 2.1(b)(i) of the Loan Agreement is
                  hereby amended by deleting it in its entirety and replacing it
                  with the following:

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                           "Subject to and upon the terms and conditions of this
                  Agreement, Borrowers may request Advances in an aggregate
                  outstanding amount not to exceed the amount of the Committed
                  Revolving Line at any one time. Amounts borrowed pursuant to
                  this Section 2. 1 (b) may be repaid and reborrowed at any time
                  prior to the Revolving Maturity Date, at which time all
                  Advances under this Section 2. 1 (b), together with all
                  accrued and unpaid interest thereon, shall be immediately due
                  and payable. Borrowers may prepay any Advances without penalty
                  or premium."

                           2.2      Section 2.1(b)(iii) of the Loan Agreement is
                  hereby amended by deleting it in its entirety.

                           2.3      Section 5.3 of the Loan Agreement is hereby
                  amended by deleting the second, third and fourth sentences
                  contained therein.

                           2.4      Section 6.2(f) of the Loan Agreement is
                  hereby amended by deleting it in its entirety and replacing it
                  with the following:

                           "(f) within 30 days of any changes to the
                  Intellectual Property Collateral and within 30 days of the
                  last day of each fiscal year, a report signed by Borrowers, in
                  form reasonably acceptable to Bank, listing any applications
                  or registrations that Borrowers have made or filed in respect
                  of any Patents, Copyrights or Trademarks and the status of any
                  outstanding applications or registrations, as well as any
                  change in Borrowers' Intellectual Property Collateral,
                  including but not limited to any subsequent ownership right of
                  any Borrower in or to any Trademark, Patent or Copyright not
                  specified in Exhibits A, B, and C of the Intellectual Property
                  Security Agreements delivered to Bank by Borrowers in
                  connection with this Agreement."

                           2.5      Paragraph (a) of Section 6.2 (relating to
                  the Borrowing Base Certificate) is deleted in its entirety and
                  replaced with the word "Reserved".

                           2.6      Section 6.7(a) is hereby amended by deleting
                  the reference to "at least 2 times its outstandings" and
                  replacing it with "at least 1.5 times its outstandings".

                           2.7      Exhibit A (DEFINITIONS) of the Loan
                  agreement is hereby amended as follows:

                                    2.7.1    The following definitions are
                  deleted in their entirety. "Borrowing Base, "Current Assets",
                  "Current Liabilities", "Eligible Accounts", "Eligible Foreign
                  Accounts", "Non-Formula Amount", "Quick Assets", "Tangible Net
                  Worth" and "Total Liabilities".

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                                    2.7.2   In the definition of "Committed
                  Revolving Line", the reference to "$3,000,000" is deleted and
                  replaced with "$4,000,000";

                                    2.7.3   In the definition of "Equipment
                  Line", the reference to "$1,500,000" is deleted and replaced
                  with "$367,175.37";

                           2.8      Exhibit D (BORROWING BASE CERTIFICATE) of
                  the Loan Agreement is hereby deleted and replaced with the
                  word "Reserved".

                           2.9      Exhibit E (COMPLIANCE CERTIFICATE) of the
                  Loan Agreement is hereby deleted and replaced with the
                  Compliance Certificate attached hereto as Annex I.

                  3.       Cancellation of Availability of Equipment Advances.
Borrowers acknowledge and agree that the outstanding principal balance of
Equipment Advances as of the date hereof is $367,175.37, and that no other
Equipment Advances will be made by Bank.

                  4.       Ratification and Reaffirmation of Liens. Borrowers
hereby ratify and reaffirm the validity and enforceability of all of the liens
and security interests heretofore granted pursuant to the Loan Documents, as
collateral security for the Obligations, and acknowledge that all of such liens
and security interests, and all Collateral heretofore pledged as security for
the Obligations, continues to be and remains Collateral for the Obligations from
and after the date hereof.

                  5.       Representations And Warranties. Each Borrower
represents and warrants that its representations and warranties in the Loan
Documents continue to be true and complete in all material respects as of the
date hereof after giving effect to this Amendment (except to the extent such
specifically relate to another date) and that the execution, delivery and
performance of this Amendment are duly authorized, do not require the consent or
approval of any governmental body or regulatory authority and are not in
contravention of or in conflict with any law or regulation or any term or
provision of any other agreement entered into by such Borrower.

                  6.       Full Force And Effect; Entire Agreement. Except to
the extent expressly provided in this Amendment, the terms and conditions of the
Loan Agreement and the other Loan Documents shall remain in full force and
effect. This Amendment and the other Loan Documents constitute and contain the
entire agreement of the parties hereto and supersede any and all prior
agreements, negotiations, correspondence, understandings and communications
between the parties, whether written or oral, respecting the subject matter
hereof. The parties hereto further agree that the Loan Documents comprise the
entire agreement of the parties thereto and supersede any and all prior
agreements, negotiations, correspondence, understandings and other
communications between the parties thereto, whether written or oral respecting
the extension of credit by Bank to Borrowers and/or their affiliates.

<PAGE>

                7. Counterparts. This Amendment may be executed in any number of
counterparts, each of which when so delivered shall be deemed an original, but
all such counterparts taken together shall constitute but one and the same
instrument.

                8. Conditions Precedent to Effectiveness. The effectiveness of
this Amendment is conditioned upon receipt by Bank of (a) this Amendment, (b) a
fully-executed corporate resolution in form and substance acceptable to Bank,
(c) an additional warrant to purchase stock in the form attached hereto as Annex
II, (d) a fully-earned, non-refundable loan restructuring fee in the amount of
$2,500, and (e) any other documents which Bank may require to carry out the
terms hereof

         In Witness Whereof, each of the parties hereto has caused this
Amendment to be executed and delivered by its duly authorized officer as of the
date first written above.

                                     Borrowers:

                                     InPhonic, Inc.

                                     By: /s/ David A. Steinberg
                                        ______________________
                                     Name:
                                     Title:

                                     SimIpc Acquisition Corp.

                                     By: /s/ David A. Steinberg
                                         ______________________
                                     Name.
                                     Title:

                                     Bank:

                                     Comerica Bank-California

                                     By: /s/ Bradley Steel
                                        ______________________
                                     Name:
                                     Title:

<PAGE>

                                     ANNEX I

                                    Exhibit E

                             COMPLIANCE CERTIFICATE

TO:     Comerica Bank - California

FROM:  InPhonic, Inc./SimIpc Acquisition Corp.

The undersigned authorized officer of Borrowers hereby certify that in
accordance with the terms and conditions of the Second Amended and Restated Loan
and Security Agreement between Borrowers and Bank (as amended, the "Agreement"),
(i) Borrowers are in complete compliance for the period ending ________________
with all required __________, including without limitation Section 6.7 except as
noted below and (ii) all representations and warranties ______________ stated in
the Agreement are true and correct in all material respects as of the date
hereof. Attached herewith are the required documents supporting the above
certification. The Officer further certifies that these are prepared in
accordance with Generally Accepted Accounting Principles (GAAP) and are
consistently applied from one period to the next except as explained in an
accompanying letter or footnotes.

Please indicate compliance status by circling Yes/No under "Complies" column.

<TABLE>
<CAPTION>
Reporting Covenant                    Required                                            Complies
------------------                    --------                                            --------
<S>                                   <C>                                                 <C>
Monthly financial statements          Monthly within 30 days                              Yes          No
Annual (CPA Audited)                  FYE within 120 days                                 Yes          No
10K and 10Q                           (as applicable)                                     Yes          No
IP Report                             Annual within 30 days and within 30 days of any     Yes          No
                                      change

Financial Covenant                    Required                  Actual                    Complies
------------------                    --------                  ------                    --------

Cash coverage ratio:                  1:50:1.00                 _____:1.00                Yes          No

                                                             -----------------------------------------------
Comments Regarding Exceptions:  See Attached.                BANK USE ONLY

                                                             Received by:___________________________________
                                                             AUTHORIZED SIGNER
Sincerely,
                                                             Date:_________________________________________

______________________________________                       Verified:______________________________________
SIGNATURE                                                    AUTHROIZED SIGNER

______________________________________                       Date:__________________________________________
TITLE

                                                             Compliance Status               Yes      No
______________________________________                       -----------------------------------------------
DATE
</TABLE>

<PAGE>

                                     ANNEX H

                           [Warrant to Purchase Stock]

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