Key differences between the AMT and the OECD BEPS rules
As an introductory comment, it is noteworthy that the US has signed up to the OECD’s common approach as an IF member, but the introduction of this new US AMT seems to have deviated from the agreed common approach. While the AMT shares some similarities with the Pillar Two GloBE effective tax rate (ETR) calculation methodologies, in that both use financial statement income as the starting point for the 15% ETR calculation, the scope and technical design of the AMT deviates from OECD architecture in material ways.
Given the differences summarised below, it seems unlikely this AMT would be considered a Qualified Domestic Minimum Top-up Tax, or Qualified Income Inclusion Rule. This raises many new issues and considerations that may result in unexpected complexities.
That said, subject to a yet-to-be-agreed Pillar Two peer review process, it is possible that the AMT may be treated as a “CFC Tax Regime” under the GloBE rules, at least to the extent that the AMT taxation is imposed in relation to the overseas profits of a US MNE. Furthermore, there is currently no agreed GloBE rule allocation methodology for how one jurisdiction’s CFC tax liability would be re-allocated to a different jurisdiction. Using a yet to-be-developed allocation CFC allocation methodology under the GloBE rules may raise further complexity when computing country-by-country ETRs.
While the AMT shares some similarities with the Pillar Two GloBE rules, it deviates in a few material ways as follows.
Threshold
With respect to scope, the AMT uses a USD 1 billion consolidated income threshold, which is based on an average annual adjusted financial statement income (AFSI) test over a three-consecutive-year period. Whereas Pillar Two GloBE rules use a EUR 750 million consolidated revenue threshold in 2 out of 4 preceding years. Also, if the corporation is a member of a foreign-parented multinational group, the USD 1 billion AFSI threshold test is modified. There are also apparent differences between Excluded Entities under GloBE rules and an ”applicable corporation” under the AMT rules.
Timing
As mentioned above, the application date for the AMT is 2023, whereas the GloBE rules are anticipated to apply from 2024 in major jurisdictions, based on the latest information available.
Calculation Methodology
With respect to the calculation methodology, the AMT and Pillar Two GloBE rules also deviate from one another. Unfortunately, the AMT calculation methodology moves away from the OECD’s common approach (i.e. agreeing a consistent set of rules) to aid overall compliance. For example, the AMT allows various US domestic tax credits, whereas the GloBE rules would treat nominated credits as a reduction to covered taxes. The OECD took this position to achieve consistency in ETR determination across many foreign jurisdictions with many different tax credit and tax offset regimes.
Another significant difference is that the GloBE rules utilise deferred tax accounting numbers in the ETR numerator to deal with potential ETR volatility from temporary differences. By contrast, the AMT determines taxes without any reference to book deferred tax accounts. There are also significant differences with the way carry forward tax losses are utilised.
The AMT is a globally blended calculation methodology that mixes high taxed and low taxed jurisdictions together. This is fundamentally different to the jurisdictional approach adopted under the GloBE rules.
As a result of these and other differences in calculation methodologies, US AMT taxpayers could still have an ETR that is lower than 15% and thus be exposed to the Income Inclusion Rule and / or the Undertaxed Payments Rule under the GloBE rules.
