Effective Tax Rate (ETR)

Definition

Effective Tax Rate (ETR) in the context of OECD Pillar Two refers to the Jurisdictional Effective Tax Rate—the ratio of Adjusted Covered Taxes to Net GloBE Income for all constituent entities in a given jurisdiction. ETR is calculated only for jurisdictions with positive Net GloBE Income. If the jurisdictional ETR falls below 15%, top-up tax is due.

This GloBE-specific ETR differs from other ETR measures (statutory rate, GAAP ETR, cash ETR) because both the numerator (taxes) and denominator (income) are subject to specific GloBE adjustments from financial accounting starting points.

OECD/Regulatory Reference

The Jurisdictional ETR calculation is defined in Article 5.1 of the GloBE Model Rules (20 December 2021).

Article 5.1.1 provides the formula:

"The Effective Tax Rate of an MNE Group for a jurisdiction for a Fiscal Year is the sum of the Adjusted Covered Taxes of each Constituent Entity located in that jurisdiction for the Fiscal Year divided by the Net GloBE Income of that jurisdiction for the Fiscal Year."

Key related provisions:

• Chapter 4 — Covered Taxes and adjustments (including Article 4.4 for deferred tax)
• Chapter 3 — GloBE Income computation and adjustments

In Practice

ETR Formula:

Jurisdictional ETR = Adjusted Covered Taxes ÷ Net GloBE Income

Where:

Key Adjustments to Covered Taxes (Numerator):

• Include: Current income tax expense accrued in financial statements
• Include: Taxes paid in lieu of corporate income tax (qualifying taxes)
• Include: Total Deferred Tax Adjustment Amount (Article 4.4) — deferred tax effects are reflected through this mechanism, not excluded
• Adjust: Uncertain tax positions, tax credits, withholding taxes (specific rules)

Key Adjustments to GloBE Income (Denominator):

• Start: Financial accounting net income/loss
• Adjust: Excluded dividends and excluded equity gains/losses
• Adjust: International shipping income exclusion (if applicable)
• Adjust: Stock-based compensation (election available to substitute local tax deduction)
• Adjust: Prior period errors and changes in accounting principles
• Note: Excluded Entities (e.g., pension funds, governmental entities) are excluded from scope entirely, not as income adjustments

Example

Facts (Jurisdiction K):

ETR Calculation:

Jurisdictional ETR = 8 / 100 = 8%

Top-Up Tax Determination:

ETR (8%) < Minimum Rate (15%) → Top-up tax applies
Top-Up Tax % = 15% − 8% = 7%
Top-Up Tax = 7% × Excess Profit (Net GloBE Income − SBIE)

(Note: This example is simplified and ignores SBIE, de minimis exclusion, and QDMTT reductions.)

ETR Comparisons

Safe Harbour ETR Tests

The Transitional CbCR Safe Harbour includes a Simplified ETR Test that allows MNEs to use simplified data as a proxy:

Simplified ETR = Simplified Covered Taxes ÷ Profit (Loss) before Income Tax

Important: The denominator comes from the Qualified CbC Report (Profit/Loss before Income Tax), but the numerator (Simplified Covered Taxes) is derived from Qualified Financial Statements—it is the income tax expense after eliminating non-Covered Taxes and uncertain tax positions. This is not simply "CbCR tax accrued."

If the Simplified ETR meets the Transition Rate for the fiscal year, the jurisdiction qualifies for safe harbour treatment (top-up tax deemed zero without full GloBE calculations).

Low ETR Drivers

Common reasons a jurisdiction may have low GloBE ETR:

Related Terms

• Pillar Two / GloBE Rules — Framework using ETR as the trigger
• Top-Up Tax — What applies when ETR < 15%
• Substance-Based Income Exclusion — Reduces income subject to top-up
• Country-by-Country Report — Data source for simplified ETR tests

Further Reading

• Global Minimum Tax Guide — ETR calculation details
• Pillar Two Safe Harbours Guide — Simplified ETR tests
• Pillar Two & CbCR Hub — All Pillar Two resources

Frequently Asked Questions

What ETR triggers Pillar Two top-up tax?

If the Jurisdictional ETR (as calculated under GloBE rules) falls below 15%, top-up tax applies to bring the effective rate to 15%.

Is ETR calculated per entity or per jurisdiction?

Per jurisdiction. All constituent entities in a jurisdiction are aggregated. This is a fundamental design principle that prevents manipulation through multiple entities in the same jurisdiction.

Can ETR be negative?

The denominator (Net GloBE Income) can be negative (loss jurisdiction), but ETR is only calculated for jurisdictions with positive Net GloBE Income. Loss jurisdictions typically don't trigger top-up tax in the loss year but may be able to make a GloBE Loss Election to create a GloBE Loss Deferred Tax Asset.

How does deferred tax affect GloBE ETR?

Deferred tax effects are reflected through the Total Deferred Tax Adjustment Amount under Article 4.4 of the Model Rules. This is different from GAAP ETR treatment. The adjustment mechanism includes caps, exclusions for certain items, and recapture rules. The common misconception that "deferred tax is excluded" is incorrect—it is adjusted through this specific mechanism.

Why might GloBE ETR differ from GAAP ETR?

• Different tax definitions: GloBE Adjusted Covered Taxes use Article 4.4 deferred tax mechanism and have specific adjustment rules
• Different income definitions: Net GloBE Income has specific exclusions and adjustments
• Different scope: GloBE is jurisdictional; GAAP may be entity-level or consolidated

Can high taxes in one jurisdiction offset low taxes in another?

No. ETR is calculated separately for each jurisdiction. A 25% ETR in Country A does not offset a 5% ETR in Country B. Top-up tax is due for Country B regardless of Country A's rate.

What if ETR is exactly 15%?

If ETR = 15%, the Top-Up Tax Percentage is zero (15% − 15% = 0%), so no top-up tax applies. The jurisdiction has met the minimum rate.