Trading Window

MAHANAGAR TELEPHONE NIGAM LIMITED (A GOVERNMENT OF INDIA ENTERPRISE) CIN L32101DL1986GOI023501 Registered and Corporate Office: Mahanagar Doorsanchar Sadan 5th Floor, 9 CGO Complex, Lodhi Road, New Delhi - 110 003. Tel: 011-24319020, Website: www.mtnl.in Email: mtnlcsco@gmail.com MTNL/SECTT/SE/2026 September 14, 2026 To, To, BSE Limited, National Stock Exchange of India Limited (NSE) Phiroze Jeejeebhoy Towers, Dalal Street, Fort, Exchange Plaza, Plot No. C/1, G Block Bandra Kurla Mumbai – 400 001. Complex, Bandra (East), Mumbai – 400 051 Scrip Code: 500108 Scrip Symbol: MTNL SUB: NOTICE FOR CLOSURE OF TRADING WINDOW IN COMPLIANCE WITH SEBI (PROHIBITION OF INSIDER TRADING) REGULATIONS, 2015 Notice is hereby given that during the period as notified below, the “Trading Window” shall remain closed and the Designated Persons and their Immediate Relatives, as defined under Clause 2.8 and 2.10 respectively of the “Internal Code of Conduct for Prevention of Insider Trading in Dealing with securities of MTNL” and Clause 4 of Schedule B of SEBI (PIT) Regulations, 2015, shall not trade in securities (involving Purchase or Sale of Shares) of MTNL either in their own name or in the name of their immediate relatives. “Designated Person” includes person as mentioned in Regulation 9(4) of SEBI (PIT) Regulations, 2015 as amended. The Designated Persons to be covered by the Code of Conduct will be on the basis of their role and function in the organization and the access that such role and function would provide to Unpublished Price Sensitive Information in addition to Seniority and Professional designation. Also, only such list of Employees as disclosed by the Company at regular intervals will be Designated Person. “Immediate Relative” means a spouse of a person, and includes parent, sibling, and child of such person or of the spouse, any of whom is either dependent financially on such person, or consults such person in taking decisions relating to trading in securities. Purpose of Closure of Trading Window Start Date of Closure Date of Opening of Trading of Trading Window Window Consideration and Approval of Unaudited 01.10.2026 Till 48 hours after the Declaration Reviewed Financial Results of MTNL for of Financial Results. the Quarter ended 30th September, 2026 (RATAN MANI SUMIT) COMPANY SECRETARY