The Australian Taxation Office (ATO) updated its instructions for the Combined global and domestic minimum tax return (CGDMTR) on 4 August 2026. The revised guidance is intended to help in-scope multinational enterprise (MNE) groups understand and meet their Pillar Two obligations, with particular attention to GloBE joint ventures, GloBE partnerships, permanent establishments, trusts, and other unincorporated group entities.
Who is in scope
An MNE group falls within the Australian Pillar Two regime if its annual revenue, as reported in the ultimate parent entity's consolidated financial statements, equals or exceeds €750 million in at least two of the four fiscal years preceding the test year. The regime is enacted through the *Taxation (Multinational–Global and Domestic Minimum Tax) Act 2024* (the Minimum Tax Act), which implements the OECD GloBE Model Rules.
Certain entities are excluded from operation of the Minimum Tax Act altogether. Others may be exempt, under Legislative Instrument LI 2025/28, from lodging one or both of the Australian IIR/UTPR Tax Return (AIUTR) and the Domestic Minimum Tax Return (DMTR).
The CGDMTR and its four sections
The CGDMTR is an online form that consolidates three distinct lodgment obligations: the foreign lodgment notification, the AIUTR, and the DMTR. The instructions cover four sections:
- **Section 1: Client information** — entity identifiers, addresses, and entity type.
- **Section 2: Group entities and combined return** — disclosure of details for each group entity, IIR and DMT top-up tax amounts (including nil), and lodgment notification requirements.
- **Section 3: Local and foreign lodgment notification** — whether the GloBE Information Return (GIR) is lodged in Australia or by an overseas designated filing entity.
- **Section 4: Lodgment summary** — finalisation and submission.
A CGDMTR Appendix provides a glossary and reference tables, including parent entity type classifications relevant to IIR reporting.
Designated lodging entities and multi-entity returns
Where a Designated Lodging Entity (DLE) is appointed, it may lodge a single combined return on behalf of all group entities. Section 2 requires the DLE to include details for each entity it represents, specifying whether a foreign lodgment notification applies and recording each entity's top-up tax amounts. Groups with more than 20 entities are directed to seek alternative lodgment arrangements.
Entities that join or leave an MNE group mid-fiscal year must lodge separately; they cannot be included in a combined DLE return.
UTPR timing and IIR reporting
The Undertaxed Profits Rule (UTPR) does not apply until fiscal years beginning on or after 1 January 2025, so UTPR top-up tax does not arise for earlier periods. IIR top-up tax is payable under section 6 of the Minimum Tax Act; DMT top-up tax is payable under section 8. Entities in circumstances described in paragraph 11(1)(a) of LI 2025/28 — where an IIR top-up tax amount could never exceed nil — may elect to report nil or select "No" to that item in Section 2.
The GIR may be lodged with the ATO directly or, where an activated exchange relationship exists between Australia and the relevant jurisdiction, filed overseas by the ultimate parent entity or designated filing entity. The ATO references the OECD list of jurisdictions with a GIR MCAA or equivalent agreement with Australia for this purpose.
The CGDMTR is available through Online services for business and through Online services for agents.
Primary sources
- CGDMTR instructions (all sections)
- Section 1: Client information
- Section 2: Group entities and combined return
- Section 3: Local and foreign lodgment notification
- Section 4: Lodgment summary
- CGDMTR Appendix
- About the CGDMTR
- Lodging, paying and other obligations for Pillar Two
- Legislative Instrument LI 2025/28
- OECD GloBE Model Rules (Pillar Two)