Resources and Reserves

The FY25 exploration program delivered a significant increase in Mineral Resources to 70.7Moz and Ore Reserves to 22.3Moz over the 12-month period to 31 March 2025, post depletion.

Maintaining our Resource and Reserve levels is crucial to achieving our five-year strategy to grow production to 2Moz per annum.

Mineral Resources as at 31 March 2025

NOTES:
1. Mineral Resources are 100% NST attributable; and inclusive of Ore Reserves.
2. Mineral Resources are reported at A$3,000oz Au for Australian assets and US$2,000/oz Au for USA assets.
3. Rounding may result in apparent summation differences between tonnes, grade and contained metal content.
4. Competent Person: Jabulani Machukera (other than Central Tanami Project JV)

Ore Reserves as at 31 March 2025

NOTES:
1. Ore Reserves are 100% NST attributable; and reported at A$2,250oz Au for Australian assets and US$1,725/oz Au for USA assets.
2. Rounding may result in apparent summation differences between tonnes, grade and contained metal content.
3. Ounces are estimates of metal contained in the Ore Reserve and do not include allowances for processing losses.
4. Competent Person: Jeff Brown

Northern Star acquired De Grey Mining Ltd by way of a scheme of arrangement implemented on 5 May 2025, resulting in Northern Star owning 100% of the Hemi Project. As this Annual Mineral Resources and Ore Reserves Statement is for the 12 months ended 31 March 2025 (i.e. prior to the implementation of the Scheme), this Statement does not include the Mineral Resources or Ore Reserves for the Hemi Project.

For further details, including a full breakdown of each project's Mineral Resources and Ore Reserves, see Northern Star's ASX release titled 'Resources, Reserves and Exploration Update' dated 15 May 2025, also available at ASX Announcements.

Competent Persons Statements

The information in this announcement that relates to exploration results, data quality and geological interpretations for the Northern Star’s Operations is based on, and fairly represents, information compiled by Daniel Howe, a Competent Person who is a Member of the Australasian Institute of Mining and Metallurgy and a full-time employee of Northern Star Resources Ltd. Mr Howe has sufficient experience that is relevant to the styles of mineralisation and type of deposits under consideration and to the activity being undertaken to qualify as a Competent Person as defined in the 2012 Edition of the "Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves". Mr Howe consents to the inclusion in this announcement of the matters based on his information in the form and context in which it appears.

The information in this announcement that relates to Mineral Resource estimations for the Northern Star’s Operations (other than the Central Tanami Gold Project) is based on, and fairly represents, information compiled by Jabulani Machukera, a Competent Person who is a Member of the Australasian Institute of Mining and Metallurgy and a full-time employee of Northern Star Resources Ltd. Mr Machukera has sufficient experience that is relevant to the styles of mineralisation and type of deposits under consideration and to the activity being undertaken to qualify as a Competent Person as defined in the 2012 Edition of the "Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves". Mr Machukera consents to the inclusion in this announcement of the matters based on his information in the form and context in which it appears.

The information in this announcement that relates to Ore Reserve estimations for the Northern Star’s Operations is based on, and fairly represents, information compiled by Jeff Brown, a Competent Person who is a Member of the Australasian Institute of Mining and Metallurgy and a full-time employee of Northern Star Resources Ltd. Mr Brown has sufficient experience which is relevant to the style of mineralisation and type of deposit under consideration and to the activity being undertaken to qualify as a Competent Person as defined in the 2012 Edition of the "Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves". Mr Brown consents to the inclusion in this announcement of the matters based on his information in the form and context in which it appears.

The information in this announcement that relates to the Central Tanami Gold Project is extracted from the Tanami Gold NL (Tanami Gold) ASX announcement entitled “Annual Mineral Resource Statement” released by Tanami Gold on 14 September 2023 and is available to view on www.tanami.com.au and www.asx.com.au. The Company confirms that it is not aware of any further new information or data that materially affects the information included in the original market announcement entitled “Annual Mineral Resource Statement” released on 14 September 2023 and, in the case of estimates of Mineral Resources, that all material assumptions and technical parameters underpinning the estimates in the relevant market announcement continue to apply and have not materially changed. To the extent disclosed above, the Company confirms that the form and context in which the Competent Person’s findings are presented have not been materially modified from the original market announcement. Northern Star Resources Ltd holds a 50% interest in the Central Tanami Gold Project. The estimate has been prepared on a 100% basis, and Northern Star has reported its attributable share in this announcement.