OECD Pillar Two · 2026 operational guide
OECD Pillar Two in 2026: Global Minimum Tax for Multinational Groups
Decision first: Pillar Two is not a 15% headline-rate test. An in-scope group must calculate a separate GloBE effective tax rate for each jurisdiction, identify any top-up tax after the substance-based exclusion, apply safe harbours, and determine which country collects under the QDMTT, IIR and UTPR ordering rules. The first practical question is therefore not “where is our rate below 15%?” but “can our consolidation, tax and entity data support the jurisdiction-by-jurisdiction computation and filing?”
Who is within the Pillar Two scope?
The OECD GloBE Model Rules generally apply to multinational enterprise groups with annual consolidated revenue of at least €750 million in at least two of the four fiscal years immediately preceding the tested year. EU Directive 2022/2523 also applies the framework to large-scale domestic groups within the European Union.
The threshold is tested using the ultimate parent entity’s consolidated financial statements, with specific rules for mergers, demergers and short fiscal years. Certain entities—including governmental entities, international organisations, non-profit organisations, pension funds and qualifying investment funds or real-estate investment vehicles that are ultimate parents—may be excluded. Their subsidiaries and ownership chains still require careful classification.
| Screening question | Why it matters | Data owner |
|---|---|---|
| Was consolidated revenue at least €750m in two of four prior years? | Determines the primary scope test. | Group consolidation team. |
| Which entity is the UPE? | Controls consolidation, filing architecture and IIR analysis. | Legal, tax and finance. |
| Are any entities excluded? | Excluded-entity status can change the group perimeter and computations. | Legal and tax. |
| Where are constituent entities located? | The ETR and top-up tax are calculated jurisdiction by jurisdiction. | Entity management and tax. |
How the 15% calculation actually works
For each jurisdiction, the group aggregates the GloBE income or loss and adjusted covered taxes of its constituent entities. The jurisdictional effective tax rate is broadly adjusted covered taxes divided by net GloBE income. The computation begins from financial-accounting income and then applies extensive GloBE adjustments; it is not the domestic taxable base divided by current tax expense.
If the jurisdictional ETR is below 15%, the top-up percentage is broadly the difference between 15% and that ETR. It is applied to excess profit after the substance-based income exclusion, with further adjustments and allocation rules. Deferred taxes, losses, tax credits, uncertain tax positions, intra-group transactions and post-filing tax changes can materially alter the result.
| Layer | Core computation | Frequent error |
|---|---|---|
| GloBE income | Financial-accounting result plus required GloBE adjustments. | Using domestic taxable income. |
| Covered taxes | Current and eligible deferred taxes after allocation and adjustments. | Using the statutory rate or total tax expense unchanged. |
| Jurisdictional ETR | Adjusted covered taxes ÷ net GloBE income. | Testing each legal entity separately. |
| Excess profit | Net GloBE income less the substance-based income exclusion. | Treating payroll and tangible assets as a full exemption. |
| Top-up tax | Top-up percentage applied to excess profit, subject to adjustments. | Applying 15% directly to accounting profit. |
Who collects the top-up tax: QDMTT, IIR and UTPR
The rules operate in an agreed order designed to prevent duplicate collection. A Qualified Domestic Minimum Top-up Tax allows the low-tax jurisdiction to collect domestic top-up tax first. The Income Inclusion Rule generally charges top-up tax at the level of the ultimate parent or another relevant parent. The Undertaxed Profits Rule operates as a backstop when low-taxed income is not fully captured by a qualified IIR.
| Rule | Function | Operational question |
|---|---|---|
| QDMTT | Domestic top-up tax in the low-tax jurisdiction. | Is the local regime qualified, and does its safe harbour apply? |
| IIR | Parent-level inclusion of top-up tax. | Which parent applies the rule under the ownership chain? |
| UTPR | Backstop allocation across implementing jurisdictions. | What residual amount remains, and how is it allocated? |
A local tax described as “minimum tax” is not necessarily a qualified QDMTT. Qualification status and the applicable OECD peer-review outcomes must be checked for the relevant fiscal year.
Italian implementation: three minimum-tax instruments
Italy implemented EU Directive 2022/2523 through Title II of Legislative Decree 209/2023. The legislation provides the Italian equivalents of the IIR, UTPR and QDMTT: imposta minima integrativa, imposta minima suppletiva and imposta minima nazionale.
An Italian constituent entity cannot limit its work to the Italian corporate return. The group must map Italian financial-accounting data into the GloBE framework, identify covered taxes, deferred-tax attributes, eligible payroll and tangible assets, tax credits, elections and intra-group allocations. Italian incentives must be classified by their economic and legal characteristics because refundable and non-refundable credits may affect GloBE income and covered taxes differently.
The Italian analysis must be reconciled with IRES, IRAP, CFC inclusions, withholding taxes, tax consolidation and transfer-pricing adjustments. Pillar Two does not replace those regimes; it adds another computational and reporting layer.
Safe harbours in 2026: simplification requires evidence
The Transitional Country-by-Country Reporting Safe Harbour can remove the full GloBE computation for a jurisdiction when the applicable de minimis, simplified ETR or routine-profits test is satisfied using qualified CbCR and financial-statement data. The OECD’s January 2026 Side-by-Side package extended the transitional CbCR safe harbour by one year and introduced further simplifications, including a Simplified ETR Safe Harbour and a Substance-based Tax Incentives Safe Harbour.
The same package created Side-by-Side and UPE safe-harbour mechanisms for groups headquartered in jurisdictions recognised as having eligible regimes. Eligibility is not a self-declared status and does not neutralise QDMTTs. A group must verify the current recognition, effective date, fiscal-year conditions and local implementation before relying on relief.
“Safe harbour” does not mean “no file.” The group still needs a documented perimeter, consistent source data, elections, local notifications and evidence that the test was met.
U.S.-headed groups: Pillar Two, Section 951A and CAMT are not the same tax
U.S.-headed multinational groups must model GloBE alongside the U.S. controlled-foreign-corporation regime, Section 951A inclusion rules, Subpart F, foreign tax credits and the corporate alternative minimum tax where applicable. These systems use different tax bases, blending rules, credit mechanics and timing conventions. A U.S. effective rate above 15% on a consolidated or federal basis does not by itself eliminate foreign QDMTT or GloBE exposure.
The 2026 OECD Side-by-Side package may change the IIR and UTPR analysis for an eligible U.S.-headed group, but qualification and jurisdictional implementation must be confirmed. QDMTT exposure in countries where the group operates remains a separate workstream.
| Difference | GloBE | U.S. regimes |
|---|---|---|
| Blending | Generally jurisdictional. | Depends on the particular U.S. rule. |
| Starting point | Consolidated financial-accounting income with adjustments. | U.S. tax-law bases and statutory adjustments. |
| Tax credits | GloBE covered-tax and credit classification. | Separate foreign-tax-credit limitations and baskets. |
| Collection | QDMTT, IIR and UTPR ordering. | Federal tax imposed under the relevant Internal Revenue Code provision. |
The real implementation problem is data
Pillar Two requires information that is rarely held in one system: consolidation adjustments, entity-level current and deferred taxes, ownership, tax residency, permanent establishments, payroll, tangible assets, tax credits, elections and CbCR data. The tax team cannot reconstruct this reliably after year-end without finance, legal, HR and local-country owners.
- Confirm scope and perimeter. Reconcile the legal-entity register to consolidation and CbCR.
- Run a jurisdictional data-gap assessment. Identify missing tax, payroll, asset and deferred-tax fields.
- Test safe harbours first. Preserve qualified source data and document elections.
- Build the full calculation where required. Reconcile GloBE income, covered taxes and SBIE.
- Map collection rights. Apply QDMTT, IIR and UTPR in order.
- Prepare filing governance. Assign the GIR, local notifications, review controls and sign-off.
- Model transactions prospectively. Acquisitions, disposals, restructurings and tax incentives can change the result.
Five mistakes that create avoidable exposure
- Testing statutory tax rates instead of the GloBE jurisdictional ETR.
- Assuming a CbCR safe harbour from the published CbCR without validating qualified data.
- Ignoring deferred-tax recapture, post-filing adjustments and tax-credit classification.
- Calculating top-up tax without applying the QDMTT–IIR–UTPR ordering rules.
- Treating Pillar Two as a tax-only project and discovering data gaps after the reporting deadline.
Frequently asked questions
What is the Pillar Two revenue threshold?
The general threshold is €750 million of consolidated annual revenue in at least two of the four fiscal years preceding the tested year, subject to detailed rules for group changes and short periods.
Does Pillar Two simply impose a 15% corporate tax rate?
No. It calculates a GloBE effective tax rate separately for each jurisdiction using adjusted financial-accounting income and covered taxes, then computes any top-up tax on excess profit.
How did Italy implement Pillar Two?
Italy implemented EU Directive 2022/2523 through Title II of Legislative Decree 209/2023, introducing an Italian IIR, UTPR and domestic minimum top-up tax.
Does a safe harbour eliminate Pillar Two compliance?
No. A safe harbour can simplify or remove the full jurisdictional calculation, but scope, qualified data, elections, notifications and evidence of eligibility still need to be documented.
Are U.S. Section 951A rules equivalent to Pillar Two?
No. Section 951A, Subpart F, the U.S. corporate alternative minimum tax and GloBE use different bases, blending, credits and collection mechanisms and must be modelled separately.
What is the GloBE Information Return?
The GIR is the standardised information return containing the group, jurisdictional and top-up-tax data required by the GloBE framework, supplemented where necessary by local notifications and filings.
Primary sources
Build a jurisdictional Pillar Two workstream
ITA International Tax & Advisor supports multinational groups with scope analysis, Italian implementation, U.S.–Italy interaction, safe-harbour testing and cross-border data mapping.