Summary of Ioneer (IONR) Update / Briefing September 03, 2025 Company Overview - **Company**: Ioneer (IONR) - **Project**: Rhyolite Ridge, a lithium and boron deposit of strategic importance to the United States Key Points and Arguments 1. **Project Economics Upgrade**: A significant upgrade to the economics of the Rhyolite Ridge project was announced, with the NPV increasing by 38% to just under $1,900,000,000 [3][12] 2. **Production Capacity**: The project has an ore reserve of 260,000,000 tons, allowing for an 82-year mine life with a production rate of 3,000,000 to 3,200,000 tons per annum, up from 2.4 to 2.6 million tons previously [4][5] 3. **Cost Efficiency**: The all-in sustaining cash cost is positioned in the bottom quartile at $5,626 per ton of lithium carbonate equivalent, benefiting from a boron credit that significantly reduces costs [5][20] 4. **Resource Potential**: The total resource is over 540,000,000 tons, indicating substantial potential for future expansion in lithium and boron production [8][24] 5. **Debt Financing**: A loan of just under $1,000,000,000 has been secured from the US government, which is a low-cost, long-term financing option [7][12] 6. **Production Transition**: The project will initially produce lithium carbonate before transitioning to lithium hydroxide, with a 20% increase in hydroxide production expected [10][11] 7. **EBITDA Growth**: Average annual EBITDA is projected to increase by 22% from $406,000,000 to $497,000,000 [12] 8. **Operational Readiness**: The project is fully permitted, shovel-ready, and has over 70% of the engineering completed, which is ahead of most mining projects at this stage [6][22] 9. **Strategic Partnerships**: Ioneer is in the process of securing an equity partner, with Goldman Sachs involved in the partnering process [25][51] 10. **Government Support**: Strong backing from both federal and state governments, emphasizing the importance of critical minerals projects [55][58] Additional Important Insights 1. **Boron Revenue Contribution**: The project is expected to produce over 100,000 tons of boric acid annually, contributing significantly to the overall economics [20][21] 2. **Unique Deposit Characteristics**: Rhyolite Ridge is noted for its unique physical properties, allowing for efficient leaching and high recovery rates [33][42] 3. **Market Demand**: The US government is focused on securing domestic supply chains for critical minerals, which aligns with the strategic importance of the Rhyolite Ridge project [59][60] 4. **Future Growth Pathways**: The company is exploring various pathways for future growth and expansion of the project, indicating a proactive approach to scaling operations [34][35] 5. **Strategic Review of Competitors**: The strategic review of Rio Tinto's borates business highlights the competitive landscape and the strategic value of boron assets [46][47] This summary encapsulates the critical updates and strategic insights from the Ioneer briefing, emphasizing the project's economic viability, operational readiness, and alignment with government priorities in the critical minerals sector.

Rhyolite Ridge Project Material Improvement in Project Economics For personal use only INVESTOR PRESENTATION September 2025 : IONR ASX : INR www.ioneer.com B Li 1 Disclaimer This presentation has been prepared as a summary only and does not contain all information about ioneer Ltds (ioneer or the Company) assets and liabilities, financial position and performance, profits and losses, prospects, and the rights and liabilities attaching to ioneer's securities. The securities issued by ioneer are considered sp ...

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 20-F ☐ REGISTRATION STATEMENT PURSUANT TO SECTION 12(b) OR (g) OF THE SECURITIES EXCHANGE ACT OF 1934 OR ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended June 30, 2024 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 ☐ SHELL COMPANY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of event req ...

Project Development and Financing - Ioneer has made significant progress towards a Final Investment Decision (FID) and construction commencement at the Rhyolite Ridge Lithium-Boron Project, supported by a $25 million share placement[4]. - The company expects to receive a positive Record of Decision from the Biden administration in October 2024, allowing for large-scale procurement post-FID[5]. - Ioneer has secured a conditional loan commitment of up to $700 million from the U.S. Department of Energy for the construction of the Rhyolite Ridge Project[8]. - The company has completed key permitting milestones, including the issuance of Air Quality and Water Pollution Control Permits, with the Mine Plan of Operations approval expected in October 2024[6]. - The project continues to advance through the NEPA permitting process, achieving key milestones including the issuance of the draft EIS in April 2024[23]. - The company anticipates achieving a Final Investment Decision (FID) by FY2025, which is crucial for future projects[124]. Resource Estimates and Exploration - The updated Mineral Resource Estimate (MRE) for the South Basin at Rhyolite Ridge shows a Measured Resource increase from 44Mt to 75Mt, representing a 71% increase[6]. - Total Mineral Resource decreased to 351 million tonnes (mt) in FY2024 from 360 mt in FY2023, with a 71% increase in Measured Resource to 75 mt[20]. - The company completed 53 drill holes in its geotechnical program, extending the lithium-boron deposit by an additional 1 km to the south and southeast[11]. - The company is focused on developing the Rhyolite Ridge Project, with an estimated resource that is open to the north, south, and east, not including the north basin tenements[27]. Financial Performance - The Group reported a net loss after tax of $7,825,000 for FY2024, compared to a loss of $6,391,000 in FY2023, indicating an increase in losses by approximately 22%[19]. - Operating cash flows improved to $(7,198,000) in FY2024 from $(8,069,000) in FY2023, reflecting a positive change of $871,000[20]. - The company reported a total revenue of $1,893,150 million for the fiscal year 2024, representing a significant increase compared to previous years[120]. - The company reported a total of 6,486,978 million in user data, indicating a strong user base growth[120]. - The company reported a total of 5,758,522 shares at June 30, 2024, compared to 5,319,954 shares at June 30, 2023[114]. Offtake Agreements and Collaborations - The company has binding offtake agreements for over 80% of its expected total production of 22,000 tonnes per annum (tpa) of lithium carbonate from Rhyolite Ridge[9]. - Ioneer is collaborating with Sibanye-Stillwater, which has committed $490 million for a 50% interest in the joint venture to develop the project[8]. - The company has entered into binding offtake agreements for the supply of boric acid from the project, which include conditions precedent related to the timing of the Final Investment Decision and first production[28]. - A binding lithium clay R&D Memorandum of Understanding was signed with EcoPro Innovation Co. Ltd to develop a 1 million tonne lithium carbonate equivalent clay resource[14]. Environmental and Compliance - Ioneer continues to maintain compliance with environmental permits, with no compliance issues reported during the year[8]. - The Draft Environmental Impact Statement (EIS) was published on April 19, 2024, initiating a 45-day public comment period, which closed in early June[6]. - The company remains committed to sustainability, achieving no lost time incidents or fatalities during the year[9]. - The company is managing risks associated with climate change, including extreme weather events that could impact future production infrastructure[31]. Risk Management - The company faces material business risks including health, safety, environmental risks, funding risk, and global economic conditions that could impact performance[27]. - The company has identified litigation risk as a potential issue that could adversely affect its financial position and performance[29]. - The company is exposed to sovereign risk related to the fiscal, tax, and regulatory environment in the jurisdictions where it operates[30]. - The Group does not undertake any hedging activities, exposing it to credit, liquidity, capital management, and market risks[191]. Executive Remuneration and Performance - The Board assessed the performance of the Company team as generally meeting expectations, awarding a Short-Term Incentive of 100% of target opportunity[60]. - The executive KMP FY2024 STI scorecard award was 50% of maximum, with individual rewards ranging from 41% to 53% of maximum[64]. - The maximum Short-Term Incentive (STI) opportunity for the Executive Chair is 120% of base salary, and for the Managing Director, it is 160%[84]. - The performance measures for the FY2024 STI scorecard include achieving a Record of Decision for the NEPA permitting process, with a maximum weighting of 40%[89]. - The company adopted an executive incentive claw-back policy during FY2024 to recover paid STI and vested LTI awards under certain circumstances[66]. Shareholder Value and Market Performance - The closing share price decreased to $0.15 in 2024 from $0.34 in 2023, highlighting a significant drop in market valuation[99]. - Basic loss per share increased to $0.336 in 2024 from $0.305 in 2023, reflecting a decline in shareholder value[99]. - The company achieved a 5-year total shareholder return (TSR) of 11.11%, recovering from a TSR of -5.56% in the previous year[99]. - The total comprehensive loss for the year attributable to the owners of the company was $7,870,000, compared to a loss of $8,914,000 in the previous year, indicating an improvement of about 11.7%[134]. Capital Structure and Equity - The company issued 2,325,614,708 shares as of June 30, 2024, an increase from 2,098,818,267 shares in the previous year[47]. - The Group issued 213,602,562 shares during the year ended June 30, 2024, as part of a capital raise, contributing to an increase in total issued capital[177]. - The equity raised from shares issued amounted to $25,141,000 during the year[138]. - The company has a total of 129,664,600 shares held by directors as of June 30, 2024, with James D Calaway holding 56,790,814 shares[37]. Financial Position and Assets - The company’s total assets increased to $224,475,000 as of June 30, 2024, up from $206,319,000 in the previous year, reflecting a growth of approximately 8.8%[135]. - The company’s net assets increased to $218,221,000 from $197,399,000, representing a growth of about 10.5%[135]. - The company’s total liabilities decreased to $6,254,000 from $8,920,000, a reduction of approximately 29.8%[135]. - The exploration and evaluation expenditure rose to $187,664,000, compared to $152,226,000 in the previous year, marking an increase of approximately 23.3%[135].

Project Development and Financing - The development of the Project is estimated to require approximately US$785 million, with a conditional commitment of up to US$700 million from the U.S. Department of Energy (DOE) and a US$490 million equity contribution from Sibanye Stillwater Limited[51]. - A proposed loan of up to US$700 million from the DOE Loan Programs Office is under negotiation, which is critical for financing the construction of the Rhyolite Ridge Project[74]. - The Joint Venture with Sibanye-Stillwater is expected to close in calendar year 2024, subject to various conditions including making a Final Investment Decision (FID) and obtaining necessary project permits[73]. - The company expects to secure a US$490 million equity contribution from Sibanye-Stillwater as part of a strategic partnership, subject to conditions precedent[243]. - The company has secured binding offtake agreements for approximately 87% of its expected lithium carbonate production in the first three years, including agreements with EcoPro, Ford Motor Company, and Prime Planet Energy & Solutions[163]. Financial Performance and Position - The company has not realized any revenues to date from the sale of lithium or boron, indicating a significant reliance on future capital raises to meet operating cash flow needs[55]. - The company reported a net loss of US$6,391,000 for fiscal 2023, a decrease from a loss of US$8,503,000 in fiscal 2022, and a significant reduction from US$14,042,000 in fiscal 2021[239]. - Total current assets decreased to US$53,062,000 in fiscal 2023 from US$94,318,000 in fiscal 2022, primarily due to a reduction in cash assets[226]. - Net cash used in operating activities was US$8,069,000 in fiscal 2023, a decrease of US$1,276,000 compared to fiscal 2022[236]. - The company had cash and cash equivalents of US$52,709,000 as of June 30, 2023, down from US$94,177,000 in the previous year[240]. Risks and Challenges - The company faces risks related to mining, exploration, and mine construction, which could significantly affect profitability and cash flow[58]. - Future growth may strain financial, technical, operational, and administrative resources, potentially impacting the company's financial position[69]. - The company cannot guarantee that it will achieve profitability or positive cash flow from its mining activities, which are subject to numerous risks and uncertainties[62]. - Market disruptions may increase borrowing costs or affect access to financial markets, impacting the company's ability to execute its business plan[69]. - Cybersecurity risks may adversely affect the company's business, with potential unauthorized access to information technology systems posing significant threats[93]. Regulatory and Environmental Compliance - The company is currently seeking NEPA review and BLM approval under FLPMA to mine its properties at Rhyolite Ridge, with the permitting process being complex and time-consuming[81]. - The company has received a Water Pollution Control Permit and Class II Air Quality Permit from the State of Nevada, but there is no assurance that all necessary approvals will be obtained[82]. - The listing of Tiehm's buckwheat as an endangered species may lead to delays and restrictions in the development of the Rhyolite Ridge Project, requiring consultations with FWS[83]. - The company faces significant governmental regulations, including the U.S. Federal Mine Safety and Health Act and the Endangered Species Act, which could lead to substantial compliance costs[94]. - Compliance with extensive environmental regulations may impose substantial costs and potential liabilities, affecting capital expenditures and operational results[199]. Market Conditions and Competition - The company expects to derive revenues primarily from the sale of refined lithium and boron compounds, with prices subject to unpredictable fluctuations due to various uncontrollable factors[105]. - New and existing competitors have increased lithium supply, which has negatively impacted prices, and further production increases could exacerbate this trend[107]. - Changes in technology may lead to preferences for substitute products, potentially reducing demand for lithium batteries in various applications[106]. - The market price of the company's American Depositary Shares (ADSs) may be highly volatile, influenced by economic conditions beyond the company's control[113]. Project Details and Operations - ioneer Ltd. is developing the Rhyolite Ridge Project, a lithium-boron mine and processing facility in Esmeralda County, Nevada, holding a 100% interest in the project[148]. - The Rhyolite Ridge Project aims to produce 20,600 tonnes per annum (tpa) of lithium carbonate and 174,400 tpa of boric acid, with first production expected by calendar year 2026[167]. - The project includes a total of 66.5 million short tons classified as proved and provable reserves, with an average lithium grade of 1,800 ppm and boron grade of 15,400 ppm[174]. - The average recovery rates for lithium and boron are projected at 81.8% and 83.5% respectively for the HiB-Li processing stream[173]. - The project is currently under NEPA review, with measures in place to protect the endangered Tiehm's buckwheat species[171]. Corporate Structure and Governance - The company is classified as a foreign private issuer, allowing it to file less information with the SEC compared to domestic issuers[129]. - ioneer Ltd. is an emerging growth company and has elected to rely on exemptions from certain reporting requirements, including auditor attestation under Section 404 of the Sarbanes-Oxley Act[134]. - The company cannot assure that an active public market for the ADSs will be maintained, which may adversely affect market price and liquidity[115]. - ADS holders do not have the same rights as shareholders, including voting rights and rights to receive dividends directly[116]. - The company anticipates not paying dividends in the foreseeable future, intending to retain future earnings to finance business development[138].

As filed with the Securities and Exchange Commission on October 21, 2022 UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 20-F ☐ REGISTRATION STATEMENT PURSUANT TO SECTION 12(b) OR (g) OF THE SECURITIES EXCHANGE ACT OF 1934 OR Suite 5.03, Level 5, 140 Arthur Street North Sydney, NSW 2060, Australia (Address of principal executive offices) ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended June 30, 2022 OR ☐ TRANSITION RE ...