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“A wealth tax is unconstitutional.”

Courts in France, Spain, Switzerland and Colombia have looked at wealth taxes, and none struck one down for being a wealth tax

Spain's Constitutional Court dismissed Madrid's challenge to the solidarity tax on great fortunes by seven votes to four, and France's Constitutional Council ruled the ISF conforms to the Constitution. Germany's court asked for equal valuation and did not forbid the tax. The US Supreme Court said in 2024 that it wasn't deciding wealth taxes.

By Egalitaristen · Updated November 9, 2026 · 4 min read

People raise this objection in one country, the United States, and talk as if it applied everywhere. Courts in several countries have looked at wealth taxes, and the pattern in what they decided is clear. None struck a wealth tax down for being a wealth tax. Where they objected, they objected to a design.

#What the courts decided

France. In 2010 the Conseil constitutionnel found the articles of the ISF conform to the Constitution. It said the lawmakers meant to tax the ability to pay that comes from holding a set of assets, and that equality before public burdens does not require that only income-producing assets be taxed.^[3] In 2017 it upheld the real estate tax that replaced the ISF, striking one rule on usufruct.^[4]

Spain. In November 2023 the Constitutional Court threw out in full Madrid's challenge to the solidarity tax on great fortunes, by seven votes to four. It held that a wealth tax would be confiscatory only if it ate up the wealth itself, not the income from it. And it said that regions can reduce their own wealth tax to zero, but that doesn't stop the national parliament from creating a tax like it.^[6]

Colombia. In 2024 and 2025 the Constitutional Court received challenges to the permanent wealth tax of Law 2277 and ruled on neither on the merits. Both times it found the complaint badly argued and declined to decide.^[5] The tax stays in force. In the 2025 ruling it also noted that the law's built-in softeners, the 72,000 UVT threshold, the exclusion of part of the home and the progressive rates, cushion the tax.^[5]

Switzerland. In 1980 the Federal Supreme Court held that the property guarantee bars the state from hollowing out someone's wealth through excessive taxation, and that no single rate marks the limit. What counts is the rate, the base and how long it lasts: a heavy burden for one or a few years is fine, and a high burden that became permanent would not be.^[7]

#What courts did restrict

Germany is the case people cite. In 1995 the Constitutional Court found that land was taxed at 1964 values and everything else at current values, which breaches equal treatment, and gave parliament until the end of 1996 to fix it.^[1] It did not forbid the tax. In 2006 the court added that the "half-split" ceiling people read into the 1995 order is in neither the operative part nor the reasoning.^[2] The remedy asked of the lawmakers was equal valuation, a job of design.

In the United States the Supreme Court held in 1895 that taxes on income from property are direct taxes that must be divided among the states by population.^[9] The country answered with the Sixteenth Amendment in 1913.

#The United States, one case among several

In Moore v. United States in 2024 the Supreme Court upheld a tax on foreign companies' undistributed income and wrote that its analysis does not address taxes on holdings, wealth or net worth. It called those questions for another day.^[8] Four justices wrote that unrealised gains can't be taxed without dividing the tax among the states, which is about realisation. None decided whether a net wealth tax is constitutional.^[8]

The law professors disagree. Two argue that the belief the Constitution makes a national wealth tax impossible is wrong.^[10] Two others argue that courts should uphold wealth taxes built as indirect taxes, and that Congress can add a fallback that divides the tax among the states, plus a rebate programme for them.^[11] The question is open, and what's open can be won.

#What countries do when a constitution blocks a design

Amend the constitution. The United States did it in 1913 after the 1895 ruling. California's Proposition 40 is a state constitutional amendment and statute that adds an article to California's constitution; it was on the 3 November 2026 ballot and the result is pending.^[12]^[13]
Change the design. Germany's court asked for equal valuation and allowed several remedies. France narrowed the ISF to real estate in 2018, and the Constitutional Council upheld the narrower tax.^[1]^[4]
Create a separate tax in a space of its own. Spain's national solidarity tax stands beside the regional wealth tax that regions had cut to zero, and the Constitutional Court upheld it.^[6]
Move the tax to a lower level. Switzerland's cantons levy the wealth tax, and the Federal Supreme Court checks for confiscation case by case.^[7] California's measure is a state tax, and the federal rule on direct taxes limits Congress, not the states.^[12]

#What it comes to

A constitution is a text people can amend and courts read narrowly. The record shows courts upholding wealth taxes, declining to decide them, or asking for better valuation. The United States has an open question, a clear amendment route and several workarounds, and its own country story sets them out.

#Who says so

The German story covers the 1995 order, the French story the Conseil constitutionnel, the Colombian story the two rulings, and the United States story the federal clause and Proposition 40.

#Where to look next

This is the last page of the first twelve. The first page in the series sets out what a wealth tax is, and the page on repeals covers the European record.