Europe Energy Windfall taxes sensitivities for EUR oils following Portugal announcement

Equity Research 31 July 2026 | 9:13PM CEST

Windfall taxes sensitivities for EUR oils following Portugal announcement

With Portugal announcing a windfall tax on July 30th, in this note we run a Michele Della Vigna, CFA | theoretical exercise applying the same calculation to European majors as an Goldman Sachs Bank Europe SE - Milan indicative read-through of relative exposure to similar windfall taxes across branch

European countries. On our estimates, Repsol has the highest percentage of its Quentin Marbach | profit which could potentially be taxed in Europe at c.12%, followed by Galp and Goldman Sachs International Eni at 2.4% each. Yulia Bocharnikova | n For context, on July 30th, Portugal approved a 33% windfall tax on Goldman Sachs International extraordinary profits earned in 2026 by oil and refining companies benefiting Anastasia Shalaeva from the energy price surge following the Iran conflict. The levy will apply only to | the portion of 2026 profits that exceeds by more than 20% the average profits Goldman Sachs International

recorded in 2024 and 2025. The proposal will now be submitted to parliament Will Chen | for final approval, where it is expected to receive sufficient support to pass. Goldman Sachs International

n The measure largely mirrors the EU’s previously established “solidarity contribution” framework and revives a similar temporary tax introduced during the 2022 energy crisis and follows a joint call earlier this year from Germany, Italy, Spain, Portugal and Austria for the European Commission to reintroduce an EU-wide windfall tax amid the sharp rise in oil and gas prices post-Iran: o Within the EU, Italy introduced a one-off 50% windfall tax for 2023. The windfall tax was applied to energy companies whose 2022 income was at least 10% above their average income over 2018 to 2021. Profits above this threshold were taxed at 50% in 2023. The tax was not deductible and was capped at 25% of the value of the company’s net assets at the end of 2021. o The Austrian windfall tax was levied on profits generated in 2022 and 2023 deemed to be “excessive”, with the tax rate reaching 40% for oil and natural gas companies. Companies that reinvested their windfall profits into projects to convert to renewable energies were eligible to have their windfall tax rate reduced from 40% to 33%. o Spain’s Congress voted to approve a windfall tax placing a 1.2% levy on energy companies’ net revenues. Energy companies that posted revenues

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below EUR1 bn in 2019 were not taxed. Others had to pay the tax in 2023 and 2024 on the revenues earned a year prior.

Quantifying the impact of a potential EU energy windfall taxes On our estimates, the most exposed name to a Portugal-style tax applied across the EU would be Repsol, where the resulting windfall tax charge would represent 12.0% of 2026E group EBIT. Eni and Galp come in at 2.4% each followed by BP (2.2%), TotalEnergies (1.6%), OMV (1.3%), Shell (0.8%) while Equinor (0.1%) would show only marginal impact.

Exhibit 1: Repsol has the highest percentage of its profit which could potentially be taxed in Europe, followed by Galp and Eni % of group profit which could be taxed under potential EU windfall scenario

Source: Company data, Goldman Sachs Global Investment Research

Exhibit 2: We see Repsol as the strongest beneficiary of higher refining margins in 2026, generating c.$3-4bn more EBIT than in EU 2025 EU 2026E EU Threshold Excess Windfall 2026E % of 2026E Company Avg 24-25 EBIT EBIT EBIT (1.2x avg) (>=0) tax (33%) group EBIT group EBIT Repsol 2,742 2,281 5,941 2,512 3,014 2,927 966 8,050 12.0% Eni 297 340 1, ,538 2.4% Galp 890 1,124 1,478 1,007 1, ,675 2.4% BP 755…