As we move through 2026, the Global Minimum Tax (GMT) regime, also known as GloBE or OECD BEPS 2.0 Pillar 2, has become firmly established in the global tax landscape. For the roughly 10,000 multinational companies affected worldwide, including those operating in Australia, GMT compliance is no longer a future concern. It’s a present reality that demands sophisticated data management and reporting capabilities.
What is GMT and why data matters
GMT is an internationally agreed-upon minimum rate of tax on corporate income, established by the OECD to prevent a “race to the bottom” in national tax rates. Companies with €750M+ in revenues must pay a top-up tax if income in any jurisdiction is taxed below the 15% global minimum rate.
While the policy intent is straightforward, the operational impact is anything but. GMT rules force companies to collect, analyse, and report on significantly more data than ever before. The legislation expands the scope of data required across the organisation, including organsational data (such as stock compensation and pension expenses) and Pillar Two–specific data (including elections and carryforwards).
The data challenge comes at a time when many corporate tax departments are already stretched thin.
According to the 2025 Thomson Reuters State of the Corporate Tax Department report:
- 58% are under-resourced
- 57% describe their technology posture as chaotic or reactive
- 74% expect tax technology budgets to increase in the next three to five years
- Only 26% track metrics around tax technology success
GMT compliance requires data to be gathered more frequently, from more business areas, in greater granularity, and on tighter timelines for regular calculations and filings. This work spans multiple tax rules: book tax, cash tax, cross-border, and local country requirements; where data is often fragmented and stored in inconsistent formats.
Where data management typically breaks down
Disparate systems and formats
- Data scattered across spreadsheets, email, and multiple ERP systems
- Lack of standardised data formats across jurisdictions
- Manual processes that are error-prone and time-intensive
Resource and technology constraints
- Limited personnel with both tax and technology expertise
- Fewer than 10% of corporate tax professionals actively using AI technology
- Staggered systems that cannot support complex GMT calculations
- Insufficient time for strategic data governance planning
Together, these challenges create bottlenecks that slow compliance, increase risk, and limit the tax team’s ability to focus on strategic work. Addressing them requires a coordinated approach that combines technology, process, and governance improvements.
What are the solutions for global minimum tax data management?
Use a single source of truth
Effective GMT data governance starts with centralising data from disparate systems into a single source of truth.
An integrated technology ecosystem
An integrated tax technology stack helps connect data, calculations, and compliance workflows across the organisation. For example, Thomson Reuters ONESOURCE offers connected solutions that support GMT compliance end to end:
- ONESOURCE DataFlow: Establishes a reliable data foundation
- ONESOURCE’s partnership with Orbitax provides GMT-related capabilities that perform complex GloBE calculations and scenario modelling, and automates the preparation and filing of GloBE Information Returns (GIR) and local top-up tax returns. The partnership also helps automate CbC Reporting. CbC data is the critical input for the Transitional CbC Reporting Safe Harbor
- ONESOURCE Tax Provision: Incorporates GloBE impacts into financial reporting
- ONESOURCE Indirect Compliance: Manages local country indirect tax compliance
This integrated approach helps automate workflows, establishes seamless cross platform data connectivity and minimise errors, and free tax professionals to focus on strategic analysis and risk mitigation.
How to build your GMT data readiness checklist
A phased approach allows organisations to make near-term progress while laying the foundation for long-term compliance and scalability.
Immediate/foundational actions (0–3 months)
- Audit current data sources and identify gaps
- Map data flows across jurisdictions
- Assess current technology stack capabilities
- Identify key stakeholders and data owners
Short-term implementation (3–12 months)
- Implement or scale a centralised data management system
- Deploy GMT-specific calculation tools
- Establish data governance protocols
- Train the tax team on new processes and technologies
Long-term optimisation (12+ months)
- Automate routine data collection and validation
- Integrate GMT processes with the broader tax technology stack
- Develop predictive analytics capabilities
- Continuously monitor and improve data quality
What’s next for GMT compliance
88% of corporate tax professionals believe AI will be central to their daily workflow within the next five years. As tax functions move toward AI-enabled processes, success will depend on high-quality data, new skills development, updated governance frameworks, and tight integration between AI tools and GMT-specific requirements.
In parallel, 74% of respondents prioritise automating tax processes, with a focus on:
- Automated data collection from multiple sources
- Standardised calculation engines for GMT compliance
- Real-time reporting and monitoring capabilities
- Integration with existing ERP and financial systems
To support this shift, many organisations are deploying sophisticated technology solutions, such as Orbitax Global Minimum Tax, to automate and standardise workflows and bring greater clarity to the impact of GMT.
Regulatory change isn’t a single deadline. It’s a preparation process.
If you’re working through Pillar Two data, calculations, and controls, and want confidence that first filings are defensible and repeatable, we can help. See how Thomson Reuters supports mandate‑ready execution →
