Switzerland’s implementation of the OECD global minimum tax has produced significantly lower tax receipts than projected. According to a new study by Deloitte Switzerland, the 50 largest listed Swiss groups paid a combined 243.2 million francs in top-up taxes for the 2024 financial year. This falls well short of the 1 to 2.5 billion in additional revenue that the Swiss Federal Council had initially estimated.

Of the companies analysed, only one-third were required to pay top-up taxes. The burden was concentrated among just three firms: Roche (CHF 189 million), Straumann (14 million francs), and Partners Group (18 million francs). These three accounted for over 90 percent of the total identified tax payments.

Safe Harbour Rules Drive Exemptions

One reason for the limited impact is the temporary «safe harbour» rules introduced by the OECD, which will remain in effect until 2026. These transitional provisions exempt companies from top-up taxes in a jurisdiction if certain profitability or tax rate thresholds are met.

Additionally, many of the firms already operate in jurisdictions where the effective tax rate exceeds 15 percent, the threshold set by the OECD framework. In such cases, no top-up tax is due.

Minimal Impact on Tax Rates

Switzerland has also delayed implementation of the Income Inclusion Rule — which would allow the taxation of profits from foreign subsidiaries in low-tax countries — until 2025. This delay has further limited the tax base in the regulation’s first year.

For most of the companies affected, the financial impact of the OECD minimum tax has been modest. According to Deloitte, the average increase in effective tax rate among impacted firms was just 0.72 percentage points, and only one company saw an increase of more than two percentage points.

Payments Collected by Other Jurisdictions

«The figures we have seen to date show that the OECD’s minimum tax scheme will only affect a handful of companies in Switzerland for the time being, and only very few will face a significantly higher tax burden,» said Thomas Hug, Partner Tax & Legal at Deloitte Switzerland. He added that the picture might change from 2027.

While the study identified 243.2 million francs in global top-up taxes, less than 200 million francs of that amount is expected to remain in Switzerland. Some payments are collected in other jurisdictions where the companies have operations.

Only Listed Companies

The analysis focuses exclusively on listed Swiss groups in the SMI and SMIM indices. It does not include unlisted Swiss companies or subsidiaries of foreign multinational groups, due to a lack of public data. The Federal Council has estimated that several hundred unlisted Swiss firms and several thousand foreign groups could also be subject to the OECD minimum tax in Switzerland, but the corresponding revenue impact remains unclear.

Switzerland introduced the domestic component of the OECD minimum tax on 1 January 2024, with the cross-border element set to follow in 2025. Deloitte notes that tax receipts may rise in future years if safe harbour rules expire and more countries implement the OECD framework. However, higher cantonal tax rates and increased taxation abroad may continue to limit domestic revenue gains.