October 21, 2019

David M. Maura
President and Chief Executive Officer
Mosaic Acquisition Corp.
375 Park Avenue
New York, NY 10152

       Re: Mosaic Acquisition Corp.
           Registration Statement on Form S-4
           Filed September 24, 2019
           File No. 333-233911

Dear Mr. Maura:

       We have reviewed your registration statement and have the following
comments. In
some of our comments, we may ask you to provide us with information so we may
better
understand your disclosure.

       Please respond to this letter by amending your registration statement
and providing the
requested information. If you do not believe our comments apply to your facts
and
circumstances or do not believe an amendment is appropriate, please tell us why
in your
response.

       After reviewing any amendment to your registration statement and the
information you
provide in response to these comments, we may have additional comments.

Form S-4 Registration Statement Filed on Septembe 24, 2019

Cover Page

1.     Please disclose that Blackstone will control the combined company
following the merger.
2.     Please revise to include the shares being registered on behalf of
selling stockholders.
3.     Refer to the third paragraph on the proxy statement/consent solicitation
       statement/prospectus cover page. Please explain your references to "New
Vivint Parent"
       and "New Vivint Parent Class A common stock and public warrants" on
first use so that it
       is clear that "New Vivint Parent" refers to Mosaic Acquisition Corp.
after the merger and
       that you are applying to list the on the NYSE the securities currently
held by Mosaic
       stockholders and the securities being issued to Vivint Smart Home
stockholders in the
       business combination. In this regard, you may wish to explain that you
are referring to
 David M. Maura
FirstName LastNameDavid M. Maura
Mosaic Acquisition Corp.
Comapany NameMosaic Acquisition Corp.
October 21, 2019
Page 2
October 21, 2019 Page 2
FirstName LastName
         Mosaic after the merger as New Vivint Parent because you intend to
change Mosaic's
         name to Vivint Smart Home, Inc. after the merger and this avoids
confusion when
         describing the parties in this document.
Questions and Answers
What will Vivint Smart Home Stockholders receive in the Merger?, page iv

4.       Please explain briefly how the exchange ratio was determined. Disclose
the total number
         of Mosaic shares that will be issued to Vivint Smart Home shareholders
in connection
         with the proposed merger, including pursuant to the treatment of
equity plans of the Vivint
         group. Also disclose the number of shares that could be issued
pursuant to the earn-out
         contingency.
What are the material United States Federal income tax consequences to Vivint
Smart Home
stockholders?, page xv

5.       We note your representation that "Vivint Smart Home and Mosaic intend
the merger to
         qualify as a `reorganization' within the meaning of Section 368(a) of
the U.S. Internal
         Revenue Code of 1986, as amended (the `Code') and/or a transaction
governed by
         Section 351 of the Code for U.S. federal income tax purposes."
Notwithstanding that the
         receipt of tax opinions is not a condition to the merger, please
provide a tax opinion as an
         exhibit and make corresponding changes to your disclosures concerning
the material tax
         consequences within the body of your prospectus. Please refer to
Section III.A. of Staff
         Legal Bulletin 19, Legality and Tax Opinions in Registered Offerings.
Summary
Debt Repayment, page 16

6.       Disclose the total outstanding debt of Vivint Smart Home and its
subsidiaries and the
         amount that would have to be paid to redeem or repurchase all of the
2020 notes issued by
         APX. Explain the importance of repaying the 2020 notes as a result of
certain debt
         agreements containing "springing maturity" provisions. In this regard,
we note
         management's plan on page F-37 to use the merger and related
investments to help
         address the substantial doubt expressed by Vivint Smart Home's auditor
about the ability
         of Vivint Smart Home to continue as a going concern.
Organizational Structure, page 17

7.       Please revise the first diagram to indicate the percentage ownerships
held by each group
         of shareholders of Vivint Smart Home and Mosaic prior to the merger.
Ownership of New Vivint Parent, page 18

8.       Please include in the table the former Class F common stockholders
(including the
         Sponsor). Also disclose the total ownership of Blackstone and its
affiliates, and highlight
         that Blackstone will control New Vivint Parent after the merger.
 David M. Maura
FirstName LastNameDavid M. Maura
Mosaic Acquisition Corp.
Comapany NameMosaic Acquisition Corp.
October 21, 2019
Page 3
October 21, 2019 Page 3
FirstName LastName
Risk Factors
Vivint Smart Home has recorded net losses in the past., page 53

9.       Please revise to quantify the net losses for the periods you have
identified.
Mosaic stockholders will have a reduced ownership and voting interest after the
merger., page 57

10.      Please revise to quantify the reduced ownership and voting interest
Mosaic shareholders
         will experience assuming various levels of redemptions.
Mosaic and Vivint Smart Home will incur transaction costs in connection with
the merger., page
61

11.      To the extent practicable, please revise to provide an estimate of the
costs each party will
         incur in connection with the proposed merger.
Affiliates of Blackstone will control New Vivint, and their interests may
conflict with New
Vivint's or yours in the future., page 66

12.      Discuss whether there will be any structural protections intended to
minimize or protect
         against conflicts of interest that may arise between New Vivint Parent
and Blackstone. For
         example, disclose whether directors who owe fiduciary duties to both
New Vivint Parent
         and Blackstone will participate in decisions about arrangements
between the two
         companies.
Unaudited Pro Forma Condensed Combined Financial Information, page 70

13.      Please clarify if certain of the converted equity awards held by your
employees and
         holdback executives will vest in full as of the effective time of the
merger. If so,
         please identify such awards and their respective number of shares/
units that will vest in
         full and give effect to the vesting in the pro forma balance sheet.
14.      Give pro forma effect to the spin-off of Vivint Wireless Inc. and
disclose the facts and
         circumstances of the spin-off in the introduction to the pro forma
information.
Unaudited Pro forma Condensed Combined Statement of Operations for the Year
Ended
December 31, 2018, page 80

15.      Considering the significant number of equity awards and conversions
reflected in the
         aggregate in Notes AA and BB, please provide a schedule summarizing
the resultant post-
         merger stock compensation expense arising from the modification of
each class of
         security (of which $18.7 million was given pro forma effect in 2018)
and the average
         number of years over which such expense will be recognized. Include
your assumptions
         regarding the fair values of the Vivint Solar Inc. and Vivint Smart
Home common stock
         and the tracking units (313 acquisition's pro rata interests in the
VSLR common stock,
         New Vivint Parent Class A common stock, and Vivint Wireless Inc.
common stock) into
         which Class B and Class A units are convertible.
 David M. Maura
Mosaic Acquisition Corp.
October 21, 2019
Page 4
16.      Please include a note disclosing any material non-recurring
merger-related charges or
         credits which will be incurred during the 12 months succeeding the
merger, including but
         not limited to the potential impact of the first and second earnouts
if and when they occur
         during that period. Refer to Rule 11-02(b)(5) of Regulation S-X.
17.      Please include a note depicting the components (arising from
conversions and issuances)
         comprising pro forma weighted average 306,312,435 shares.
Mosaic Proposals
Proposals No. 2 through No. 12 -- The Charter Proposals, page 94

18.      Identify the "Stockholder Parties" referenced in the new charter
provisions.
Vivint Smart Home's Management's Discussion and Analysis of Financial Condition
and
Results of Operations, page 181

19.      Disclose that Vivint Smart Home's auditors have expressed substantial
doubt that it will
         be able to continue as a going concern. Discuss management's plans to
address Vivint
         Smart Home's recurring net losses, negative cash flows from
operations, and substantial
         indebtedness subject to contractual terms that will accelerate
maturity of such
         indebtedness if it has not made specified debt repayments prior to
September 1, 2020.
Key Performance Measures, page 182

20.      To avoid confusion, please ensure that your definitions of Total
Subscribers and Total
         Monthly Revenue on pages 182 and 183 are the same as your definitions
of Total
         Subscribers and Total MR in the Glossary on page ii. Please advise and
revise as
         appropriate.
Year Ended December 31, 2018 Compared to the Year Ended December 31, 2017
Costs and Expenses , page 198

21.      We note that general and administrative expenses increased in part due
to increases in
         personnel and related costs of $25.4 million. To the extent material,
please disclose how
         much of the personnel and related costs were attributable to the 2018
retention awards and
         incremental stock-based compensation expense arising from the June
2018 modifications
         of equity awards.
Liquidity and Capital Resources, page 201
FirstName LastNameDavid M. Maura
Comapany NameMosaic Acquisition Corp. of cash proceeds from the transactions
that will be
22.    Please revise to indicate the amount
October 21, 2019 Page 4 of the purposes you identify at points i, ii, and iii
on page 202.
       allocated for each
FirstName LastName
 David M. Maura
FirstName LastNameDavid M. Maura
Mosaic Acquisition Corp.
Comapany NameMosaic Acquisition Corp.
October 21, 2019
Page 5
October 21, 2019 Page 5
FirstName LastName
The Merger, page 225

23.      Discuss whether and how Mosaic's board determined that the business
combination with
         Vivint Smart Home will meet the NYSE requirement that the initial
business combination
         must occur with one or more operating businesses or assets with a fair
market value equal
         to at least 80% of the net assets held in the trust account.
Unaudited Prospective Financial Information of Vivint Smart Home, page 226

24.      We note that financial projections were prepared and considered by the
Vivint Smart
         Home and Mosaic boards in connection with the proposed transaction.
Please disclose the
         basis for and the nature of the material assumptions underlying the
projections. Provide us
         with these projections, and any similar materials furnished to board
members. Upon
         review, we may have further comment.
Background of the Merger, page 227

25.      Revise to discuss how the exchange ratio, treatment of Vivint group
equity plans, and
         number of earn-out shares were determined.
Recommendation of the Mosaic Board of Directors and Reasons for the Merger,
page 238

26.      We note at bullet point six on page 239 that the Mosaic board
considered factors such as
         "Vivint Smart Home's historical financial results, outlook, financial
plan, and debt
         structure, as well as valuations and trading of publicly traded
companies and valuations of
         precedent merger and acquisition targets in similar and adjacent
sectors." Please revise to
         provide more fulsome disclosure addressing the material findings of
the board's
         consideration of these several factors.
Selling Stockholders, page 247

27.      We note that you list Solamere V Investment, LLC as a selling
stockholder; however, you
         disclose in footnote (1) that the shares are being sold by affiliates
of Solamere V
         Investment, LLC. Please revise to name each selling stockholder.
Financial Statements
Note 2. Significant Accounting Policies
Capitalized Contract Costs, page F-47

28.      We note it is your policy to amortize deferred contract costs on a
straight-line basis over
         the expect period of benefit that the Company has determined to be
five years. Please
         address in your policy disclosure the following and advise us in
detail.
           Explain to us why you do not amortize deferred contract costs over
the customer's
              contract term, consistent with your revenue recognition policy.
           With respect to customer contracts that do not require a long-term
commitment for
              monitoring services, explain to us why the material right to
renew has a period of
 David M. Maura
FirstName LastNameDavid M. Maura
Mosaic Acquisition Corp.
Comapany NameMosaic Acquisition Corp.
October 21, 2019
October 21, 2019 Page 6
Page 6
FirstName LastName
              benefit of three years, and not the five year period utilized for
purposes of
              amortization of deferred contract costs.
              In light of a majority of your subscription contracts being
between three and five
              years in length, explain why a five year amortization is
appropriate for these
              contracts.
              Tell us how you account for unamortized deferred contract costs
upon the termination
              of a customer relationship.
              Address in your policy disclosure your consideration of the
guidance in ASC 340-40-
              35-2 and advise us.
17. Basic and Diluted Net Loss Per Share, page F-81

29.      Please disclose the potential effect of issuing shares related to the
SARs and RSUs which
         have been excluded from the computation of diluted net loss per share
as their effect
         would have been antidilutive.
1. Basis of Presentation and Significant Accounting Policies, page F-96

30.      Please include a note disclosing common stock equivalents that were
excluded from your
         calculation of weighted-average shares as their effect would have been
anti-dilutive.
Notes to Condensed Consolidated Financial Statements (Unaudited)
10. Stock-based Compensation, page F-117

31.      With respect to 313 Incentive Units, Vivint Stock Appreciation Rights
, and Restricted
         Stock Units, please disclose accelerated vesting terms upon a change
in control, as
         applicable. Clarify if the change in control provision applies to
executives and employees
         alike. Please further disclose their respective conversion or exchange
terms.
32.      Please disclose the fair values of the Restricted Stock Units awarded
in June 2018 and
         March, 2019 (page F-118) and how they were determined.
General

33.      We note that the Maximum Redemption Condition may be waived by Vivint
Smart
         Home. Therefore, please revise your disclosure throughout the document
so that it also
         contemplates a maximum redemption amount that leaves Mosaic with at
least $5,000,001
         of tangible net assets. Also disclose how you will inform each
company's stockholders if
         this condition is waived.



        We remind you that the company and its management are responsible for
the accuracy
and adequacy of their disclosures, notwithstanding any review, comments, action
or absence of
action by the staff.
 David M. Maura
Mosaic Acquisition Corp.
October 21, 2019
Page 7

       Refer to Rules 460 and 461 regarding requests for acceleration. Please
allow adequate
time for us to review any amendment prior to the requested effective date of
the registration
statement.

        You may contact Kathryn Jacobson, Staff Accountant, at 202-551-3365 or
Robert S.
Littlepage, Accounting Branch Chief, at 202-551-3361 if you have questions
regarding
comments on the financial statements and related matters. Please contact Paul
Fischer, Staff
Attorney, at 202-551-3415 or Kathleen Krebs, Special Counsel, at 202-551-3350
with any other
questions.



FirstName LastNameDavid M. Maura                           Sincerely,
Comapany NameMosaic Acquisition Corp.
                                                           Division of
Corporation Finance
October 21, 2019 Page 7                                    Office of Technology
FirstName LastName