Mattr Corp. — Proxy Solicitation & Information Statement 2026

Apr 14, 2026

NOTICE OF ANNUAL MEETING OF SHAREHOLDERS

NOTICE IS HEREBY GIVEN that the annual meeting (the "Meeting") of shareholders of Mattr Corp. (the "Company") will be held on May 14, 2026, at 2:00 p.m., EDT, in person at the Sheraton Centre Toronto, 123 Queen Street, Toronto, Ontario in the Wentworth Room, 2nd Floor and via a virtual meeting format by way of a live webcast at https://meetings.lumiconnect.com/400-645-184-700. A user guide for the Lumi virtual meeting platform is attached to this Notice. Shareholders will have the opportunity to attend, ask questions and vote at the meeting in real time either in person or through the Lumi virtual meeting platform. The Meeting is being held for the following purposes:

1. to receive the annual financial statements of the Company for the year ended December 31, 2025 and the report of the auditor thereon (the "Financial Statements");
2. to elect directors of the Company for the ensuing year;
3. to appoint the auditor of the Company for the ensuing year and to authorize the directors to fix the auditor's remuneration;
4. to approve, on an advisory basis, the compensation for our named executive officers; and
5. to transact such other business as may properly be brought before the Meeting.

The Management Information Circular of the Company (the "Circular") contains details of matters to be considered at the Meeting and accompanies and is deemed to form part of this notice.

Notice-and-Access

The Company has elected to use the notice-and-access ("Notice-and-Access") provisions under National Instrument 54-101 – Communications with Beneficial Owners of Securities of a Reporting Issuer and National Instrument 51-102 – Continuous Disclosure Obligations to distribute meeting materials to shareholders. Under Notice-and-Access, shareholders continue to receive a proxy or voting instruction form enabling them to vote at the Meeting. However, instead of a paper copy of the Circular and Financial Statements, shareholders will receive this Notice of Meeting which contains information on how to access the Circular and Financial Statements electronically under the Company's profile on SEDAR+ at www.sedarplus.ca and on one additional website. Shareholders have the right to request hard copies of any proxy-related materials posted online by the Company under Notice-and-Access.

The Circular and the form of proxy (or voting instruction form) includes additional information regarding the matters to be dealt with at the Meeting. Disclosure regarding the matters to be discussed at the Meeting can be found in the Circular under section 1 and information related to voting can be found in the Circular under section 1. Shareholders are reminded to review the meeting materials prior to voting. Shareholders with questions regarding the Notice-and-Access process may contact the Company's transfer agent, Odyssey Trust Company ("Odyssey Trust"), by telephone at 1-888-290-1175 (toll-free within North America) or 1-587-885-0960 (direct from outside North America).

Websites where Meeting Materials are Posted

Meeting materials, including the Circular and the Financial Statements, are available under the Company's profile on SEDAR+ at www.sedarplus.ca and also on the Company's website at https://www.mattr.com/proxy-materials-annual-financials/.

Obtaining Paper Copies of Meeting Materials

The Company will provide to any shareholder, free of charge, upon request to Odyssey Trust Company via toll free at 1-888-290-1175 (toll-free within North America) or 1-587-885-0960 (direct from outside North America) or by email https://odysseytrust.com/ca-en/help/, a paper copy of the Circular and any financial statements or management's discussion and analysis of the Company filed with the applicable securities regulatory authorities during the past year. In order to allow reasonable time for you to receive and

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review a paper copy of the Circular or other document prior to the proxy deadline, you should make your request for a paper copy to Odyssey Trust by 5:00 p.m. on May 5, 2026.

Voting

It is desirable that as many shares as possible be represented at the Meeting. If you would like your shares represented at the Meeting, please complete, date and sign the enclosed form of proxy and return it in the envelope provided to the Company's transfer agent, Odyssey Trust Company, Proxy Department, Suite 1100 – 67 Yonge Street, Toronto, Ontario, M5E 1J8, Canada or by e-mail: proxy@odysseytrust.com or fax to: 1-800-517-4553 or vote online at https://vote.odysseytrust.com and enter the 13 digit control number on your form of proxy or voting instruction form. Proxies must be received by the transfer agent not later than May 12, 2026, 2:00 p.m., EDT. Alternatively, registered shareholders may vote in person or in real time during the Meeting through the Lumi virtual meeting platform at https://meetings.lumiconnect.com/400-645-184-700. Please review the Circular prior to voting.

DATED at Toronto, Ontario the 31st day of March, 2026.

By Order of the Board of Directors

Shannon Glover

Corporate Secretary