A growing number of OECD countries and partner economies are implementing taxes on banks and sectors considered "highly profitable" to offset increases in public expenditure, including on defence. This trend is identified in the organization's report "Tax Policy Reforms 2026", which analyses the main tax reforms introduced or announced in 2025 in 92 jurisdictions. The OECD states that there was a "noteworthy" development with the introduction or expansion of specific and sectoral taxes on business income, often temporarily and taking the form of surcharges applied to specific sectors.
Portugal is preparing to tax the surplus profits of oil extraction and refining companies obtained in 2026, through a Temporary Solidarity Contribution on the Oil Sector. The rate will be applied to the portion of profits that exceeds the average of the results of the previous two years. The proposal was approved in the Council of Ministers on 30 July and still requires parliamentary approval to be implemented.
Regarding personal income tax, the OECD identifies the trend of applying higher top rates and reforms in the taxation of capital income. In Portugal, there was a reduction in personal income tax in the first eight of the nine income brackets, followed in 2026 by a new relief from the second to the fifth bracket. Many countries continue to introduce reforms to reduce the tax base to support low and medium-income families, although on a smaller scale than in previous years.
Regarding Social Security contributions, the report points to a sustained trend of broadening the tax base and increasing rates, in response to long-term demographic pressures. In corporate income tax, the main objectives were revenue mobilisation and efforts to stimulate growth and investment, with rate increases tending to be higher than reductions, although countries continued to reduce the tax base through targeted measures to support investment.
