Please refer the enclosed file.

HZL/2026-27/SECY/86 September 28, 2026 BSE Limited National Stock Exchange of India Limited Phiroze Jeejeebhoy Towers Exchange Plaza, 5th Floor Plot No., C/l, G Block Dalal Street, Fort Bandra-Kurla Complex, Bandra (East), Mumbai – 400 001 Mumbai – 400 051 Kind Attn: General Manager – Department Kind Attn: Head Listing & Corporate of Corporate Services Communication Scrip Code: 500188 Trading Symbol: HINDZINC Dear Sir/Ma’am, Sub: Intimation of Trading Window Closure Pursuant to the Securities and Exchange Board of India (Prohibition of Insider Trading) Regulations, 2015 and the Insider Trading Prohibition Code of the Company ("Code"), the Trading Window for dealing in the securities of the Company shall remain closed for all Designated Persons and their Immediate Relatives, as defined under the Code, from Thursday, October 01, 2026, until 48 hours after the declaration of the Unaudited Financial Results (Standalone and Consolidated) of the Company for the second quarter and half year ending September 30, 2026. The date of the Board Meeting for considering the aforesaid financial results shall be intimated to the Stock Exchanges in due course. This is for your information and records. Thanking you. Yours faithfully, For Hindustan Zinc Limited Aashhima V Khanna Company Secretary & Compliance Officer Sensitivity: Public (C4)