Compliance
Global Minimum Tax Returns: What Multinational Groups Must Prepare Before Lodgment
Australia’s Global and Domestic Minimum Tax Return (CGDMTR) API introduces new reporting mandates for corporate groups—get ready for IIR, UTPR, and DMT obligations.
By NomadicTax Research Team • 5-8 min read • June 13, 2026
## Understanding Australia’s Minimum Tax Regime
Australia has implemented the OECD’s Global Anti-Base Erosion (BEPS) rules, which include:
- **Income Inclusion Rule (IIR)**
- **Under-Taxed Payments Rule (UTPR)**
- **Domestic Minimum Tax (DMT)**
These impose minimum tax burdens on multinational enterprise groups (MNEs) and require combined returns specifically for these obligations. Australia offers a dedicated API for lodging these global and domestic minimum tax returns. ([apiportal.ato.gov.au](https://apiportal.ato.gov.au/api-products/global-and-domestic-minimum-tax?utm_source=openai))
## Key Responsibilities & Timing for Multinational Groups
- Groups must submit a **Combined Global and Domestic Minimum Tax Return (CGDMTR)** using the ATO’s API products to report liabilities under IIR, UTPR, and DMT. ([apiportal.ato.gov.au](https://apiportal.ato.gov.au/api-products/global-and-domestic-minimum-tax?utm_source=openai))
- For Group Entities, the **Group Entity Tax Return API** allows reporting of these obligations, up to 300 entities in one lodgment. Ensure proper transaction IDs and other metadata are passed. ([apiportal.ato.gov.au](https://apiportal.ato.gov.au/api-products/global-and-domestic-minimum-tax?utm_source=openai))
## Practical Challenges and Compliance Tips
- Align your **financial year reporting** across all entities in the group to ensure consistency in CGDMTR.
- Use sandbox environments to test submissions if using new or modified software, especially for AMENDMENT vs ORIGINAL transaction types. ([apiportal.ato.gov.au](https://apiportal.ato.gov.au/api-products/global-and-domestic-minimum-tax?utm_source=openai))
- Track all payments, donations, transfers or dividend payments that may be subject to withholding, as mischaracterisation can lead to penalties under IIR/UTPR.
## Examples of How This Plays Out
- A multinational company with Australian subsidiaries exports intellectual property rights and earns royalties: these payments now need close review—ensure withholding obligations are met and reported via the IIR or UTPR framework.
- A company under the DMT threshold may still have liabilities if their combination of global income and tax structure trigger minimum tax obligations; transparency in reporting is crucial.
## Steps for Compliance
| Task | Who | When |
|---|---|---|
| Map all Group Entities & identify ultimate parent | Tax leaders & legal | As soon as possible |
| Review all cross-border payments | Finance teams | Before year-end |
| Plan system & API integration | Digital providers or IT & tax teams | Pre-lodgment period |
| Stay abreast of ATO guidance and test | Tax agents | Continuous |
With full obligations under the CGDMTR regime now in force, MNEs operating in Australia must ensure their systems, reporting, and governance align with these new global minimum tax requirements.