What is Pillar Two?
A clear overview of OECD Pillar Two / GloBE rules for multinational groups — scope, minimum tax concept, and how Safe Harbours fit.
Overview
“Pillar Two” refers to the OECD/G20 Inclusive Framework’s global minimum tax initiative. In common usage it centers on the Global Anti-Base Erosion (GloBE) Model Rules, which are designed so that large multinational enterprise (MNE) groups face a minimum effective tax rate on income arising in each jurisdiction where they operate.
Domestic law implements these concepts differently across countries. Software and workflows can help organize calculations and review — they do not replace interpretation of local statute or professional advice.
Who it typically applies to
At a high level, GloBE rules are aimed at MNE groups with consolidated revenue at or above a large threshold (commonly discussed as €750 million in the Model Rules framing), tested over a lookback of fiscal years. Exact scoping, exclusions, and elections depend on the applicable domestic rules and OECD guidance as adopted.
Groups should confirm whether they are in scope, which entities are Constituent Entities, and how joint ventures, investment entities, and excluded entities are treated under the rules that apply to them.
The core idea: a minimum effective tax rate
Where GloBE applies, the framework generally compares a jurisdiction’s GloBE effective tax rate (ETR) to a minimum rate (commonly 15% in the Model Rules). If income is taxed below that rate, a top-up tax amount may arise, subject to local mechanisms such as a Qualified Domestic Minimum Top-up Tax (QDMTT), the Income Inclusion Rule (IIR), and the Undertaxed Profits Rule (UTPR).
The sequencing and interaction of these charging mechanisms matter. Teams typically map which rule applies first for each jurisdiction and entity chain.
Where Safe Harbours fit
To reduce compliance burden during transition (and in some permanent forms), Inclusive Framework materials introduce Safe Harbours — tests that, if met, can allow a group to treat a jurisdiction as not requiring the full GloBE calculation path for a period or under specified conditions.
The Transitional CbCR Safe Harbour is the most widely discussed transitional relief. See our guides on Safe Harbour and the three transitional tests for orientation.
What tax teams typically need to organize
In practice, Pillar Two work combines data, calculation, review, and documentation: entity and jurisdiction inputs, test outcomes, exceptions, evidence, and reporting packs. Spreadsheets alone often struggle once review notes, version control, and multi-jurisdiction status must stay aligned.
Mirentra is decision-support software for that workflow. It does not determine legal conclusions or replace adviser judgment.
Primary sources
Start with Inclusive Framework primary materials (Model Rules, Commentary, and Safe Harbour guidance) linked in the sidebar, then confirm how your jurisdictions have enacted and administered those concepts.