Mr. Shawn Howarth reports

EXCELLON RESOURCES MOBILIZES CONTRACTOR AND COMMENCES REHABILITATION AT MALLAY SILVER MINE, PERU

Excellon Resources Inc. has mobilized a mining contractor and commenced underground rehabilitation activities at its 100-per-cent-owned Mallay silver mine in Peru. Excellon's plan to restart operations at the past-producing Mallay mine and return the company to silver production is under way.

Highlights:

• Experienced underground mining contractor mobilized to the Mallay mine to initiate rehabilitation, development and preparation works;
• Initial rehabilitation efforts focused on cleaning and reinforcing the main haulage levels of the mine (4,150 and 4,090 levels), including scaling, improving ground support and ventilation, and reopening key drifts and ramps for equipment access;
• Rehabilitation activities are expected to be completed within four months, consistent with Excellon's broader restart plan;
• As the rehabilitation phase advances, the company will be positioned to further evaluate production planning, utilizing existing advanced underground development and stope preparation;
• The current schedule keeps Excellon on track to achieve ramp up to nameplate capacity of 600-tonne-per-day production, by the second quarter of 2026.

Paul Keller, chief operating officer of Excellon, commented: "Mobilizing our mining contractor and commencing site rehabilitation at Mallay marks a pivotal operational milestone for Excellon. Our team, in partnership with an experienced Peruvian contractor, is now fully engaged in safely and responsibly rehabilitating the underground workings and preparing key areas of the mine for the next phase of development. This progress underscores the company's operational focus and commitment to executing the Mallay restart efficiently and safely, bringing Excellon closer to resuming silver production in Peru."

Next steps and upcoming milestones

Priorities over the next six months include executing a detailed Mallay restart plan and demonstrating the property-wide mineral potential beyond the existing historical resources. Key near-term milestones in the upcoming stages include:

• Completion of National Instrument 43-101 mineral resource estimate (in progress): Finalize updated resource estimate model for the Mallay mine, incorporating historical data and current metal price assumptions. This work is under way and expected to be completed by late August, 2025.
• Completion of mine rehabilitation (in progress): Continue rehabilitation of critical underground workings. This work is underway and expected to be completed by November, 2025.
• Advance operational planning: Following the updated mineral resource estimate and completion of mine rehabilitation, the company intends to advance internal mine planning and evaluate operating scenarios to support strategic decision making and restart execution.
• Production restart: Following underground rehabilitation, initiate development and stope production preparations for further production guidance.
• In-mine exploration drilling: Commencement of underground drilling, targeting extensions of known high-grade veins and new mineralized zones with a goal of expanding the resource base. This work will commence upon completion of mine rehab and contemporaneously with production restart.
• District exploration update: Concurrent with mine rehabilitation, exploration on high-priority targets in the immediate Mallay mine area, including the Pierina vein system, is under way. The company is also advancing community discussions at Tres Cerros, a 2.5-kilometre corridor of high-sulphidation epithermal alteration with robust surface mineralization and geophysical anomalies.

Qualified person

Paul Keller, PEng, Excellon's chief operating officer and a qualified person as defined by National Instrument 43-101 -- Standards of Disclosure for Mineral Projects, has reviewed and approved the technical information contained in this release.

About Excellon Resources Inc.

Excellon's vision is to realize opportunities through the acquisition and advancement of quality precious and base metal assets, leveraging an experienced management team for the benefit of its employees, communities and shareholders. The company is focused on the potential restart of the Mallay silver mine in Peru. Excellon also holds a portfolio of exploration-stage projects, including Kilgore, an advanced gold project in Idaho, and Silver City, a high-grade epithermal silver district in Saxony, Germany, and the Tres Cerros gold/silver exploration property in Peru, providing additional growth upside.

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