Effective Tax Rate (ETR) — 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.
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:
text
Jurisdictional ETR = Adjusted Covered Taxes ÷ Net GloBE Income
Where:
Component
Description
Adjusted Covered Taxes
Current tax expense from financial statements, plus Total Deferred Tax Adjustment Amount (Article 4.4), and other adjustments per GloBE rules (Chapter 4)
Net GloBE Income
Financial accounting net income/loss, adjusted per GloBE rules (Chapter 3), aggregated for all constituent entities in the jurisdiction
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: 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
Aggregation: ETR is calculated on a jurisdictional basis—all constituent entities in a jurisdiction are aggregated. This prevents manipulation through intra-jurisdictional entity structures.
(Note: This example is simplified and ignores SBIE, de minimis exclusion, and QDMTT reductions.)
ETR Comparisons
ETR Type
Numerator
Denominator
Purpose
GloBE ETR
Adjusted Covered Taxes
Net GloBE Income
Pillar Two minimum tax test
Statutory Rate
N/A
N/A
Published tax rate
GAAP ETR
Total tax expense
Pre-tax book income
Financial reporting
Cash ETR
Cash taxes paid
Pre-tax book income
Cash flow analysis
CbCR ETR
Tax accrued
Profit before tax
Risk assessment proxy
Don't Confuse ETRs: A company may have a GAAP ETR of 20% but a GloBE ETR below 15% due to differences in tax and income definitions. Each ETR serves a different purpose and uses different inputs.
Safe Harbour ETR Tests
The Transitional CbCR Safe Harbour includes a Simplified ETR Test that allows MNEs to use simplified data as a proxy:
text
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).
Fiscal Year Beginning
Transition Rate
2023 or 2024
15%
2025
16%
2026
17%
Low ETR Drivers
Common reasons a jurisdiction may have low GloBE ETR:
Driver
Description
Tax incentives
Patent boxes, R&D credits, regional incentives
Tax holidays
Temporary zero or reduced rates
Loss utilization
NOL carryforwards reducing current tax
Timing differences
Accelerated depreciation, other deferrals
Tax credits
Investment credits reducing tax liability
Transfer pricing
Profit shifted to low-tax jurisdiction
Incentive Erosion: Pillar Two effectively caps the value of tax incentives at 15%. A jurisdiction offering 5% tax rates will see the benefit reduced as top-up tax applies to bring the effective rate to 15%.
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.