VERX · Vertex, Inc.

Represents an award of restricted stock that will vest on the earlier to occur of (i) the day immediately prior to the date of the next annual meeting of the Company's stockholders, and (ii) June 10, 2027.

Represents an award of restricted stock that will vest on the earlier to occur of (i) the day immediately prior to the date of the next annual meeting of the Company's stockholders, and (ii) June 10, 2027.

Represents an award of restricted stock that will vest on the earlier to occur of (i) the day immediately prior to the date of the next annual meeting of the Company's stockholders, and (ii) June 10, 2027.

Represents an award of restricted stock that will vest on the earlier to occur of (i) the day immediately prior to the date of the next annual meeting of the Company's stockholders, and (ii) June 10, 2027.

Represents an award of restricted stock that will vest on the earlier to occur of (i) the day immediately prior to the date of the next annual meeting of the Company's stockholders, and (ii) June 10, 2027.

Represents an award of restricted stock that will vest on the earlier to occur of (i) the day immediately prior to the date of the next annual meeting of the Company's stockholders, and (ii) June 10, 2027.

Represents an award of restricted stock that will vest on the earlier to occur of (i) the day immediately prior to the date of the next annual meeting of the Company's stockholders, and (ii) June 10, 2027.

Represents an award of restricted stock that will vest on the earlier to occur of (i) the day immediately prior to the date of the next annual meeting of the Company's stockholders, and (ii) June 10, 2027.

Represents securities held by individual trusts for the benefit of the Reporting Person's three adult children. The Reporting Person's spouse serves as a trustee of each such trust.

The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $15.02 to $15.06. The reporting person hereby undertakes to provide upon request to the SEC staff, the issuer or a security holder of the issuer full information regarding the number of shares and prices at which the transaction was effected.

Each restricted stock unit represents a contingent right to receive one share of the Issuer's Class A Common Stock.

This restricted stock unit award is fully vested.

The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions ranging from $11.9832 to $12.2862 inclusive. The Reporting Person undertakes to provide to the Issuer, any securityholder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the range set forth above.

Each restricted stock unit represents a contingent right to receive one share of the Issuers Class A Common Stock.

The remaining restricted stock units will vest on February 23, 2027 and have no expiration date.

Each restricted stock unit represents a contingent right to receive one share of the Issuer's Class A Common Stock.

The remaining restricted stock units will vest on February 23, 2027 and have no expiration date.

Each restricted stock unit represents a contingent right to receive one share of the Issuer's Class A Common Stock.

The remaining restricted stock units will vest on February 23, 2027 and have no expiration date.

Each restricted stock unit represents a contingent right to receive one share of the Issuer's Class A Common Stock.

The remaining restricted stock units will vest in two equal annual installments on each of February 22, 2027 and February 22, 2028 and have no expiration date.

Each restricted stock unit represents a contingent right to receive one share of the Issuer's Class A Common Stock.

The remaining restricted stock units will vest in three equal annual installments on each of February 20, 2027, February 20, 2028 and February 20, 2029 and have no expiration date.

Includes 84 shares acquired through the Company's Employee Stock Purchase Plan.

Each restricted stock unit represents a contingent right to receive one share of the Issuer's Class A Common Stock.

The remaining restricted stock units that will vest in two equal installments on each of February 22, 2027 and February 22, 2028 and have no expiration date.

The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions ranging from $12.87 to $12.96, inclusive. The Reporting Person undertakes to provide to the Issuer, any securityholder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the range set forth above.

Each restricted stock unit represents a contingent right to receive one share of the Issuer's Class A Common Stock.

The remaining restricted stock units will vest in two equal annual installments on each of February 22, 2027 and February 22, 2028 and have no expiration date.

Each restricted stock unit represents a contingent right to receive one share of the Issuer's Class A Common Stock.

The remaining restricted stock units will vest in three equal installments on February 20, 2027, February 20, 2028 and February 20, 2029 and have no expiration date.

Each restricted stock unit represents a contingent right to receive one share of the Issuer's Class A Common Stock.

The remaining restricted stock units that will vest in three equal installments on each of February 20, 2027, February 20, 2028 and February 20, 2029 and have no expiration date.

Each restricted stock unit represents a contingent right to receive one share of the Issuer's Class A Common Stock.

The remaining restricted stock units will vest in three equal annual installments on each of February 20, 2027, February 20, 2028 and February 20, 2029 and have no expiration date.

Each restricted stock unit represents a contingent right to receive one share of the Issuer's Class A Common Stock.

The remaining restricted stock units will vest in two equal installments on February 22, 2027 and February 22, 2028 and have no expiration date.

Each restricted stock unit represents a contingent right to receive one share of the Issuers Class A Common Stock.

Represents an award of restricted stock units that will vest as to 25% of the amount of shares on each of February 19, 2027, February 19, 2028, February 19, 2029 and February 19, 2030.

Each restricted stock unit represents a contingent right to receive one share of the Issuers Class A Common Stock.

Represents an award of restricted stock units that will vest as to 25% of the amount of shares on each of February 19, 2027, February 19, 2028, February 19, 2029 and February 19, 2030.