Exhibit 99.3

                             JOINT FILING AGREEMENT

      Pursuant to and in accordance with the Securities Exchange Act of 1934, as
amended, and the rules and regulations thereunder (the "Exchange Act") the
undersigned hereby agree to the joint filing on behalf of each of them of any
filing required by such party under Section 13 or Section 16 of the Exchange Act
or any rule or regulation thereunder (including any amendment, restatement,
supplement, and/or exhibit thereto) with respect to securities of Atlas
Technical Consultants, Inc., a Delaware corporation, and further agree to the
filing, furnishing, and/or incorporation by reference of this Agreement as an
exhibit thereto. Each of them is responsible for the timely filing of such
filings and any amendments thereto, and for the completeness and accuracy of the
information concerning such person contained therein; but none of them is
responsible for the completeness or accuracy of the information concerning the
other persons making the filing, unless such person knows or has reason to
believe that such information is inaccurate. This Agreement shall remain in full
force and effect until revoked by any party hereto in a signed writing provided
to each other party hereto, and then only with respect to such revoking party.
This Agreement may be executed in any number of counterparts all of which taken
together shall constitute one and the same instrument.

      IN WITNESS WHEREOF, the undersigned hereby execute this Joint Filing
Agreement as of the 19th day of January, 2020.

                                  ATLAS TECHNICAL CONSULTANTS
                                  HOLDINGS LP

                                  By:    Atlas Technical Consultants Holdings GP
                                         LLC,
                                         its general partner

                                  By:    /s/ Chris Dillon
                                         ---------------------------------------
                                  Name:  Chris Dillon
                                  Title: Authorized Signatory


                                  ATLAS TECHNICAL CONSULTANTS
                                  HOLDINGS GP LLC

                                  By:    /s/ Chris Dillon
                                         ---------------------------------------
                                  Name:  Chris Dillon
                                  Title: Authorized Signatory


                                  BCP ENERGY SERVICES FUND, LP

                                  By:    BCP Energy Services Fund GP, LP,
                                         its general partner

                                  By:    BCP Energy Services Fund UGP, LLC,
                                         its general partner

                                  By:    /s/ Jeffrey Jenkins
                                         ---------------------------------------
                                  Name:  Jeffrey Jenkins
                                  Title: Authorized Signatory


                                  BCP ENERGY SERVICES FUND-A, LP

                                  By:    BCP Energy Services Fund GP, LP,
                                         its general partner

                                  By:    BCP Energy Services Fund UGP, LLC,
                                         its general partner

                                  By:    /s/ Jeffrey Jenkins
                                         ---------------------------------------
                                  Name:  Jeffrey Jenkins
                                  Title: Authorized Signatory


                                  BCP ENERGY SERVICES EXECUTIVE
                                  FUND, LP

                                  By:    BCP Energy Services Fund GP, LP,
                                         its general partner

                                  By:    BCP Energy Services Fund UGP, LLC,
                                         its general partner

                                  By:    /s/ Jeffrey Jenkins
                                         ---------------------------------------
                                  Name:  Jeffrey Jenkins
                                  Title: Authorized Signatory


                                  BCP ENERGY SERVICES FUND GP, LP

                                  By:    BCP Energy Services Fund UGP, LLC,
                                         its general partner

                                  By:    /s/ Jeffrey Jenkins
                                         ---------------------------------------
                                  Name:  Jeffrey Jenkins
                                  Title: Authorized Signatory


                                  BCP ENERGY SERVICES FUND UGP, LLC

                                  By:    /s/ Jeffrey Jenkins
                                         ---------------------------------------
                                  Name:  Jeffrey Jenkins
                                  Title: Authorized Signatory


                                  JAMES M. BERNHARD JR.

                                  By:    /s/ James M. Bernhard Jr.
                                         ---------------------------------------
                                  Name:  James M. Bernhard Jr.


                                  JEFFREY SCOTT JENKINS

                                  By:    /s/ Jeffrey Jenkins
                                         ---------------------------------------
                                  Name:  Jeffrey Jenkins