Exhibit 10.2

ASSUMPTION AGREEMENT, dated as of August 22, 2008, made by Helio LLC, a Delaware
limited liability company (the “Additional Grantor”), in favor of JPMorgan Chase
Bank, N.A. as Collateral Agent (in such capacity, the “Collateral Agent”) for
the banks and other financial institutions or entities (the “Lenders”) parties
to the Credit Agreement referred to below.

W I T N E S S E T H :

WHEREAS, Virgin Mobile USA, L.P., a Delaware limited partnership (formerly known
as Virgin Mobile USA, LLC) (the “Borrower”), the Lenders, and the Agents named
therein have entered into an Amended and Restated Credit Agreement, dated as of
July 19, 2006 (as amended, supplemented or otherwise modified from time to time,
the “Credit Agreement”);

WHEREAS, in connection with the Credit Agreement, the Borrower and certain of
its Affiliates (other than the Additional Grantor) have entered into the
Guarantee and Collateral Agreement, of even date with the Credit Agreement (as
amended, supplemented or otherwise modified from time to time, the “Guarantee
and Collateral Agreement”; all capitalized terms not defined herein shall have
the meaning ascribed to them in such Guarantee and Collateral Agreement) in
favor of the Collateral Agent for the benefit of the Secured Parties;

WHEREAS, the Credit Agreement requires the Additional Grantor to become a party
to the Guarantee and Collateral Agreement; and

WHEREAS, the Additional Grantor has agreed to execute and deliver this
Assumption Agreement in order to become a party to the Guarantee and Collateral
Agreement.

NOW, THEREFORE, IT IS AGREED:

1. Guarantee and Collateral Agreement. By executing and delivering this
Assumption Agreement, the Additional Grantor, as provided in Section 8.14 of the
Guarantee and Collateral Agreement, hereby becomes a party to the Guarantee and
Collateral Agreement as a Grantor thereunder with the same force and effect as
if originally named therein as a Grantor and, without limiting the generality of
the foregoing, hereby expressly assumes all obligations and liabilities of a
Grantor thereunder and hereby grants to the Collateral Agent, for the benefit of
the Secured Parties, a security interest in all of its right, title and interest
in all Collateral, whether now owned or hereafter acquired. The information set
forth in Annex 1-A hereto is hereby added to the information set forth in the
Schedules to the Guarantee and Collateral Agreement. The Additional Grantor
hereby represents and warrants that each of the representations and warranties
contained in Section 4 of the Guarantee and Collateral Agreement is true and
correct on and as the date hereof (after giving effect to this Assumption
Agreement) as if made on and as of such date.

2. Governing Law. THIS ASSUMPTION AGREEMENT SHALL BE GOVERNED BY, AND CONSTRUED
AND INTERPRETED IN ACCORDANCE WITH, THE LAW OF THE STATE OF NEW YORK.

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IN WITNESS WHEREOF, the undersigned has caused this Assumption Agreement to be
duly executed and delivered as of the date first above written.

 

HELIO LLC By:   Virgin Mobile USA, L.P., its sole member   By:   VMU GP1, LLC,
its general partner     By:   Bluebottle USA Holdings, L.P., its sole member    
  By:   Bluebottle USA Investments L.P., its general partner         By:   VMU
GP, LLC, its general partner           By:   Virgin Mobile USA, Inc., its sole
member         By:   /s/ Peter Lurie           Name:   Peter Lurie          
Title:   General Counsel and Corporate Secretary