Constellation Software : 2026 Form Proxy

320 Bay Street, 14th Floor Toronto, ON M5H 4A6 https://www.computershare.com

Security Class

Holder Account Number

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Form of Proxy - Annual Meeting to be held on May 15, 2026 This Form of Proxy is solicited by and on behalf of Management. Notes to proxy

1. Every holder has the right to appoint some other person or company of their choice, who need not be a holder, to attend and act on their behalf at the meeting or any adjournment or postponement thereof. If you wish to appoint a person or company other than the persons whose names are printed herein, please insert the name of your chosen proxyholder in the space provided (see reverse).

2. If the securities are registered in the name of more than one owner (for example, joint ownership, trustees, executors, etc.), then all those registered should sign this proxy. If you are voting on behalf of a corporation or another individual you may be required to provide documentation evidencing your power to sign this proxy with signing capacity stated. If you are voting on behalf of a corporation you are required to provide your name and designation of office, e.g., ABC Inc. per John Smith, President.

3. This proxy should be signed in the exact manner as the name(s) appear(s) on the proxy.

4. If this proxy is not dated, it will be deemed to bear the date on which it is mailed by Management to the holder.

5. The securities represented by this proxy will be voted as directed by the holder, however, if such a direction is not made in respect of any matter, this proxy will be voted as recommended by Management.

6. The securities represented by this proxy will be voted in favour or withheld from voting or voted against each of the matters described herein, as applicable, in accordance with the

   instructions of the holder, on any ballot that may be called for and, if the holder has specified a choice with respect to any matter to be acted on, the securities will be voted accordingly.

7. This proxy confers discretionary authority in respect of amendments or variations to matters identified in the Notice of Meeting or other matters that may properly come before the

   meeting or any adjournment or postponement thereof.

8. This proxy should be read in conjunction with the accompanying documentation provided by Management.

   Proxies submitted must be received by 8:30 a.m., Eastern Time, on May 13, 2026.

   VOTE USING THE TELEPHONE OR INTERNET 24 HOURS A DAY 7 DAYS A WEEK!

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   To Vote Using the Telephone

   To Vote Using the Internet

   To Virtually Attend the Meeting

   
   
   

   • Call the number listed BELOW from a touch tone

     telephone.

     1-866-732-VOTE (8683) Toll Free

   • Go to the following web site: https://www.investorvote.com

   • Smartphone?

     Scan the QR code to vote now.

   • You can attend the meeting virtually by visiting

the URL provided on the back of this document.

If you vote by telephone or the Internet, DO NOT mail back this proxy.

Voting by mail may be the only method for securities held in the name of a corporation or securities being voted on behalf of another individual.

Voting by mail or by Internet are the only methods by which a holder may appoint a person as proxyholder other than the Management nominees named on the reverse of this proxy. Instead of mailing this proxy, you may choose one of the two voting methods outlined above to vote this proxy.

To vote by telephone or the Internet, you will need to provide your CONTROL NUMBER listed below.

CONTROL NUMBER

Appointment of Proxyholder

I/We, being holder(s) of Constellation Software Inc. hereby appoint: Mark Miller, or failing him, Jamal Baksh

Print the name of the person you are appointing if

OR this person is someone other than the Management

Nominees listed herein. Beneficial shareholders

may appoint themselves as a proxyholder.

Note: If completing the appointment box above and your appointee intends to attend the meeting online YOU MUST go to http://www.computershare.com/Constellation and provide Computershare with the name and email address of the person you are appointing. Computershare will use this information ONLY to provide the appointee with a user name to gain entry to the online meeting.

as my/our proxyholder with full power of substitution and to vote in accordance with the following direction (or if no directions have been given, as the proxyholder sees fit) and all other matters that may properly come before the Annual Meeting of shareholders of Constellation Software Inc. to be held in person at Delta Hotels Toronto, 75 Lower Simcoe Street, Toronto, Ontario, M5J 3A6 and online at https://meetnow.global/MMT5Q4H on May 15, 2026 at 8:30 a.m., Eastern Time, and at any adjournment or postponement thereof.

VOTING RECOMMENDATIONS ARE INDICATED BYHIGHLIGHTED TEXT OVER THE BOXES.

1. Election of Directors

   For Withhold For Withhold For Withhold

   1. Jamal Baksh

   2. John Billowits

   3. Lawrence Cunningham

   4. Claire Kennedy

   5. Robert Kittel

   6. Mark Miller

   7. Donna Parr 08. Andrew Pastor 09. Laurie Schultz

2. Appointment of Auditors

   Re-appointment of KPMG LLP, as auditors of the Corporation for the ensuing year and to authorize the directors to fix the remuneration to be paid to the auditors.

3. Advisory Vote on Executive Compensation

An advisory vote to accept the Corporation's approach to executive compensation as more particularly described in the accompanying management information

circular.

ForWithhold

ForAgainst

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Signature of Proxyholder

I/We authorize you to act in accordance with my/our instructions set out above. I/We hereby revoke any proxy previously given with respect to the Meeting. If no voting instructions are indicated above, and the proxy appoints the Management Nominees, this Proxy will be voted as recommended by Management.

If you are voting on behalf of a corporation you are required to provide your name and

designation of office, e.g., ABC Inc. per John Smith, President.

Signature(s)

Signing Capacity

Date

DD / MM / YY

Interim Financial Statements - Mark this box if you would like to receive Interim Financial Statements and accompanying Management's Discussion and Analysis by mail.

Annual Financial Statements - Mark this box if you would like to receive the Annual Financial Statements and accompanying Management's Discussion and Analysis by mail.

If you are not mailing back your proxy, you may register online to receive the above financial report(s) by mail at https://www.computershare.com/mailinglist.

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