Portugal's 2027 Corporate Tax Cut Could End the GILTI/NCTI High-Tax Exclusion for American Owners
Portugal's general corporate income tax rate is scheduled to fall from 20% in 2025 to 19% for tax periods beginning in 2026, then to 18% for tax periods beginning in 2027, and to 17% for tax periods beginning in 2028. The change is generally framed as good news for companies operating in Portugal. For companies with American owners, the 2027 step down carries a separate and less obvious consequence on the U.S. side.
Why the Rate Change Matters for U.S. Tax Purposes
Under Treasury Regulations, a U.S. shareholder of a Controlled Foreign Corporation (CFC) can elect to exclude that CFC's tested income from GILTI (now more precisely Net CFC Tested Income, or NCTI, following the 2025 U.S. tax law changes) entirely, if the foreign effective tax rate on that income exceeds 90% of the U.S. corporate rate. With the U.S. corporate rate at 21%, that threshold is 18.9%. The OBBBA's broader 2026 changes to the GILTI/NCTI framework did not change this specific threshold. It remains 18.9%.
Portugal's rate has sat comfortably above that line at 20% and will still clear it at 19% in 2026. At 18% in 2027, it does not. This is a discrete crossover tied to a specific tax year, not a gradual erosion. A company taxed at 19% in 2026 may qualify for the high-tax exclusion. The same company taxed at 18% in 2027 may not, absent some other factor pushing its effective rate back above 18.9%.
A few variables determine where a given company actually lands, and these are worth reviewing client by client rather than assuming the statutory rate settles the question:
Municipal and state surtaxes. The derrama municipal and the state surtax on higher profit levels can push a company's effective rate above the 18% statutory figure, potentially back above 18.9% depending on the municipality and profit level involved.
SME and small mid-cap reduced rates. Companies qualifying for the reduced rate on the first €50,000 of taxable income face a different blended effective rate calculation, and the general-rate crossover analysis may not apply to them in the same way.
Effective rate versus statutory rate. The exclusion tests the rate actually paid on the tested income, not the statutory rate in the abstract. Deductions, credits, and incentives available under Portuguese law all affect where a specific company's effective rate lands relative to 18.9%.
For a company that loses the exclusion, a NCTI inclusion appears on the American owner's U.S. return where none existed before. Depending on the size of the company's tested income, this can be a material and previously unmodeled U.S. tax liability.
Particular Relevance for American IFICI Beneficiaries
This issue is especially relevant for American IFICI beneficiaries who own Portuguese companies. IFICI has been a significant draw for Americans relocating to Portugal, and much of the program's appeal rests on the local tax treatment it offers. A NCTI inclusion triggered by the 2027 rate crossover sits entirely outside that calculation and can change the overall tax picture for these individuals in two ways. First, it can add a U.S. tax cost that offsets some of the benefit the individual expected from IFICI treatment on the Portuguese side, since IFICI addresses Portuguese tax on the individual's income and has no effect on the separate U.S. liability. Second, it adds a layer of annual U.S. reporting and calculation, specifically the CFC and NCTI analysis, that these individuals and their advisors may not have needed to run in prior years when the exclusion applied automatically.
IFICI status itself has no bearing on the outcome described above. The issues here arise entirely on the U.S. side of the analysis: the CFC classification, the tested income calculation, and the 18.9% high-tax exclusion threshold. Nothing about an individual's IFICI status changes any of those inputs, because IFICI governs Portuguese taxation of the individual and does not touch the Portuguese corporate tax rate paid by the company or the U.S. CFC rules that apply to the individual as a shareholder. An American client can be fully compliant with, and benefiting from, IFICI while independently losing the high-tax exclusion on a company they own, and the two facts have no direct relationship to each other.
Coordinating Across the Two Sides
This issue falls into the gap between a Portuguese advisor's scope of work and a U.S. tax preparer's scope of work, since neither side alone typically has full visibility into both the Portuguese rate mechanics and the U.S. CFC analysis. Portuguese advisors working through this question for a specific client, or wanting a second look at whether a particular company's effective rate still clears the threshold, are welcome to reach out to Areia Global directly.
Areia Global is a cross-border consultancy based in Lisbon that supports Americans in Portugal and the institutions that serve them. This article is provided for general informational purposes and does not constitute tax or legal advice.