# EDGAR Filing Document

**Accession Number:** 0001896084
**File Stem:** 0001140361-25-036657
**Filing Date:** 2025-9
**Character Count:** 5196
**Document Hash:** eb2ea73f98dc632ac3374935daa1d52e
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001140361-25-036657.hdr.sgml**: 20250930

**ACCESSION NUMBER**: 0001140361-25-036657

**CONFORMED SUBMISSION TYPE**: 6-K

**PUBLIC DOCUMENT COUNT**: 6

**CONFORMED PERIOD OF REPORT**: 20250930

**FILED AS OF DATE**: 20250930

**DATE AS OF CHANGE**: 20250930

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** ioneer Ltd
- **CENTRAL INDEX KEY:** 0001896084
- **STANDARD INDUSTRIAL CLASSIFICATION:** MINING, QUARRYING OF NONMETALLIC MINERALS (NO FUELS) [1400]
- **ORGANIZATION NAME:** 01 Energy & Transportation
- **EIN:** 000000000
- **STATE OF INCORPORATION:** C3
- **FISCAL YEAR END:** 0630

**FILING VALUES:**
- **FORM TYPE:** 6-K
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-41412
- **FILM NUMBER:** 251358382

**BUSINESS ADDRESS:**
- **STREET 1:** 140 ARTHUR STREET
- **STREET 2:** SUITE 5.03, LEVEL 5
- **CITY:** NORTH SYDNEY
- **STATE:** C3
- **ZIP:** NSW 2060
- **BUSINESS PHONE:** 61(2)99225800

**MAIL ADDRESS:**
- **STREET 1:** 140 ARTHUR STREET
- **STREET 2:** SUITE 5.03, LEVEL 5
- **CITY:** NORTH SYDNEY
- **STATE:** C3
- **ZIP:** NSW 2060

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#### UNITED STATES

### SECURITIES AND EXCHANGE COMMISSION

#### Washington, D.C. 20549

### FORM 6-K

#### REPORT OF FOREIGN PRIVATE ISSUER

#### Pursuant to Rule 13a-16 or 15d-16 of the

#### Securities Exchange Act of 1934

#### For the month of September 2025
**Commission File Number:**001-41412

#### <br>

## ioneer Ltd
(Translation of registrant's name into English)

#### Suite 16.01, 213 Miller Street

#### North Sydney, NSW, 2060, Australia
(Address of principal executive offices)

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Indicate by check mark whether the registrant files or will file annual reports under cover of Form 20-F or Form 40-F.

Form 20-F ☒ Form 40-F ☐

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#### EXHIBIT INDEX
The following exhibits are filed as part of this Form 6-K:

<u> Exhibit </u> <br> <u> Description </u> <br> <br> [99.1](ef20056465_ex99-1.htm) Press Release

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#### SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

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| | | |
|:---|:---|:---|
|  | ioneer Ltd | ioneer Ltd |
|  | (registrant) | (registrant) |
| Date: September 30, 2025 | By:<br>| <u>/s/ Ian Bucknell</u><u> </u> |
|  | Name: Ian Bucknell | Name: Ian Bucknell |
|  | Title: Chief Financial Officer & Company Secretary | Title: Chief Financial Officer & Company Secretary |

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## Exhibit 99.1

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**Exhibit 99.1**

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| | |
|:---|:---|
| ![](image00001.jpg) | ![](image00002.jpg) |

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## Change in Financial Year End
**25 September 2025** – **Ioneer Ltd ("Ioneer") (ASX: INR, NASDAQ: IONR)** today announced that the Board of Directors of Ioneer Ltd (Ioneer) has resolved to change Ioneer's financial year from 1 July - 30 June, to 1 January - 31 December.

The change is made in accordance with section 323D(2A) of the Corporations Act 2001 (Cth). The Board confirms that:

<br> • Ioneer's current financial year will end on 31 December 2025 which will be a six-month Transitional Financial Year (TY), beginning on 1 July 2025 and ending on 31 December 2025.

<br> • Thereafter, Ioneer will adopt a twelve-month financial year, with the first commencing on 1 January 2026 and ending on 31 December 2026.

<br> • The change in financial year requires Ioneer to, in respect of the TY:

<br> o Lodge an additional annual report by March 2026.

<br> o Hold an additional annual general meeting in May 2026 (TY 2026 AGM).

Ioneer will provide further details of the TY 2026 AGM closer to the date.

This announcement has been authorised by the Board of Directors of Ioneer Ltd.

#### --ENDS—

#### <br>

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| | |
|:---|:---|
| Investor Relations | Media Relations |
| Chad Yeftich<br> Ioneer USA Corporation | Daniel Francis<br> FGS Global (USA) |
| Investor Relations (USA)<br> T: +1 775 993 8563<br> E: ir@ioneer.com<br><u> </u> | Media Relations (AUS)<br> E: <u>daniel.francis@fgsglobal.com</u> |

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**![](image00003.jpg)

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![](image00004.jpg)

### About Ioneer
Ioneer Ltd is an emerging lithium–boron producer and the 100% owner of the Rhyolite Ridge Lithium-Boron Project. Rhyolite Ridge is one of only a small number of lithium-boron ore deposits globally, and a linchpin project in Nevada's burgeoning Lithium Loop.

Rhyolite Ridge closed a US$996 million loan with the U.S. Department of Energy Loan Programs Office under the Advanced Technology Vehicles Manufacturing program in January 2025. In October 2024, Ioneer received the final federal permit for the project from the Bureau of Land Management, concluding the formal federal permitting process which began in early 2020. Ioneer signed separate offtake agreements with Ford Motor Company and Prime Planet & Energy Solutions (joint venture between Toyota and Panasonic) in 2022 and Korea's EcoPro Innovation in 2021.

To learn more about Ioneer, visit <u>www.Ioneer.com/investors</u> or join our online communities on <u>X</u>, <u>Facebook</u>, <u>LinkedIn</u>, <u>Instagram</u> and <u>YouTube</u>

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|:---|:---|
| 2.0 |  |
|  | ![](image00003.jpg) |

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