Vertex (VERX) SC 13G Vertex / Radcliffe Amanda Westphal ownership change

Exhibit 99

JOINT FILING AGREEMENT

In accordance with Rule 13d-1(k)(1) promulgated under the Securities Exchange Act of 1934, as amended, the undersigned hereby agree that they are jointly filing this statement on Schedule 13G. Each of them is responsible for the timely filing of such statement 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.

IN WITNESS WHEREOF, the undersigned hereby execute this Joint Filing Agreement as of the 12^th day of February, 2021.

/s/ Amanda Radcliffe

Amanda Radcliffe

/s/ Stefanie Thompson

Stefanie Thompson

/s/ Jeffrey Westphal

Jeffrey Westphal

/s/ Christopher Thompson

Christopher Thompson

/s/ Benjamin Schmerin

Benjamin Schmerin

/s/ Conrad Radcliffe

Conrad Radcliffe

/s/ Kailey Radcliffe

Kailey Radcliffe

/s/ Antoinette Radcliffe

Antoinette Radcliffe

/s/ Anne Marie Westphal

Anne Marie Westphal

/s/ Kyle Westphal

Kyle Westphal

/s/ Jacob Westphal

Jacob Westphal

/s/ Melanie Lucas

Melanie Lucas

/s/ Samantha Lucas

Samantha Lucas

/s/ Mackenzie Lucas

Mackenzie Lucas

/s/ Andrea Schmerin

Andrea Schmerin

/s/ Constance Thompson

Constance Thompson

/s/ Nicholas Shuhan

Nicholas Shuhan