ST. Gallen Corporate Income Tax
Last updated: 09 Dec 2025
St. Gallen Corporate Income Tax — Profit Tax Rules
How corporate income tax works in the Canton of St. Gallen: who is subject to profit tax, how the tax base is determined from accounting profit, how cantonal, communal and federal components interact, and what to know about participation relief, STAF measures and loss carryforwards.
Scope & Taxpayers
- Resident companies. Companies with statutory seat or effective place of management in St. Gallen are subject to unlimited tax liability on their worldwide income, subject to relief for foreign permanent establishments and immovable property under double tax treaties and intercantonal rules.
- Nonresident entities. Nonresident companies are limited tax liable in St. Gallen if they have local business operations, a permanent establishment, or St. Gallen–situs real estate. Only the profits attributable to the St. Gallen nexus are taxed.
- Juristic persons only. The corporate income tax described here applies to juristische Personen (AG, GmbH, cooperative, certain foundations and associations). Partnerships and sole proprietors are taxed at shareholder/owner level under personal income tax.
- Tax period. The profit tax period for juristic persons generally follows the financial year. A change of year-end or an extended first business year must be coordinated with the tax office.
Tax Base: From Accounting Profit to Taxable Profit
St. Gallen corporate income tax is levied on the company’s taxable profit, determined by starting from statutory financial statements (usually Swiss GAAP) and then making tax adjustments.
| Step | Description | Typical adjustments |
|---|---|---|
| 1. Accounting profit | Profit after tax per statutory financial statements for the relevant business year. | Profit as approved by the shareholders’ meeting, before appropriation of retained earnings. |
| 2. Add-backs | Non-deductible or partially deductible expenses are added back to profit. | Hidden profit distributions; excessive interest or royalties to related parties; non-business expenses; penalties; corporate income tax itself; some provisions. |
| 3. Deductions | Items that are tax deductible but not expensed, or expensed differently, are deducted. | Tax-allowed depreciation that exceeds accounting depreciation (within limits); specific provisions; participation relief; R&D super-deduction where applicable. |
| 4. Allocation & exemptions | Profits allocable to other cantons or foreign permanent establishments are exempt in St. Gallen under intercantonal and treaty rules. | Profit/loss attribution keys; separate determination of foreign PE income; treaty exemptions or credit methods. |
| 5. Taxable profit | Result after adjustments, before loss carryforwards and special reliefs. | Loss carryforwards of up to 7 years can be offset against current-year taxable profit (subject to general Swiss rules). |
The St. Gallen tax book (St. Galler Steuerbuch) and cantonal practice notes provide detailed guidance on depreciation, provisions, hidden equity, participation relief and other adjustments relevant for the tax base. In practice, a clear reconciliation from accounting profit to taxable profit is expected as part of the corporate tax return.
Rates & Effective Burden
Cantonal & communal profit tax
St. Gallen applies a profit tax on net income at cantonal level, combined with a communal share. For standard capital companies and cooperatives, the simple cantonal profit tax rate is 2.8% of taxable profit (since 1 January 2020). The effective rate is increased by a communal surcharge expressed as a percentage of the simple cantonal tax.
The communal share for juristic persons is levied via a unified surcharge on the cantonal tax, set as a percentage (e.g. 130%) of the simple cantonal tax and periodically adjusted by the cantonal parliament. This creates a single cantonal/communal profit tax line item for companies.
For up-to-date effective St. Gallen profit tax burdens by location, see the Rates page and the official St. Gallen company tax calculator .
Federal corporate income tax
In addition to cantonal/communal profit tax, companies pay Swiss direct federal corporate income tax at a flat rate of 8.5% on profit after tax. Because federal tax itself is deductible, this corresponds to an effective rate of about 7.8% on profit before tax.
The combined effective corporate income tax rate in St. Gallen is therefore the sum of:
- Cantonal/communal profit tax (based on the simple rate and the surcharge); and
- Direct federal corporate income tax.
The St. Gallen tax calculator on this hub allows you to model combined cantonal, communal and federal profit tax for a given level of taxable profit.
Participation Relief & STAF Measures
St. Gallen follows federal rules for participation relief and has implemented STAF (Swiss corporate tax reform and AHV financing) measures at cantonal level.
| Mechanism | Overview | Typical planning aspects |
|---|---|---|
| Participation relief | Qualifying dividends and capital gains from shareholdings in subsidiaries are effectively subject to reduced taxation via a deduction calculated on the basis of net participation income relative to total profit. | Minimum shareholding thresholds (e.g. 10% or CHF 1m market value); holding period; treatment of write-downs and liquidation proceeds; interaction with foreign withholding tax and treaty relief. |
| Patent box | Income from qualifying intellectual property can benefit from a reduced cantonal tax base under patent box rules, subject to nexus requirements and tracking of R&D expenditure. | Segregation of IP income and expenses; documentation of R&D functions; consistent methodology with OECD nexus approach; ruling practice. |
| R&D super-deduction | Certain R&D expenditures may be eligible for an additional deduction at cantonal level, reducing the profit tax base beyond the accounting expense. | Defining qualifying R&D; allocation between in-house and outsourced services; aligning tax treatment with cost accounting and transfer pricing. |
| Notional interest deduction (NID) | Depending on the legal framework and future reforms, a notional deduction on qualifying equity may be available to reduce the tax base, particularly for financing activities and treasury companies. | Identifying qualifying equity; managing thin capitalisation; interaction with interest limitation rules and group financing policies. |
The overall relief from participation deduction, patent box, R&D super-deduction and (where applicable) notional interest deduction is subject to a maximum relief cap at cantonal level. Individual structuring and advance tax rulings are common for larger businesses.
Losses, Groups & Permanent Establishments
- Loss carryforwards. Tax losses can generally be carried forward for up to 7 years and offset against future taxable profits in St. Gallen, within the standard Swiss framework. Loss carryback is not available.
- Group situation. Switzerland has no fiscal unity or tax consolidation for ordinary corporate income tax. Each St. Gallen legal entity files its own return; group effects are managed via financing, transfer pricing and participation relief.
- Intercantonal allocation. Where a company has operations, real estate or permanent establishments in several cantons, profit and capital are allocated using generally accepted keys (e.g. payroll, assets, turnover) based on practice and jurisprudence.
- Foreign permanent establishments. Under many treaties, profits attributable to foreign permanent establishments are exempt in Switzerland with progression. Accurate attribution of profits and capital is essential to support the exemption.
- Restructurings. Mergers, de-mergers, contributions in kind and migrations of seat can be tax neutral if Swiss conditions are met (continuity of business, carryover of hidden reserves, adequate consideration, etc.). Rulings are often used to secure treatment for St. Gallen and federal purposes.
Interaction with Capital Tax
Corporate income tax and capital tax are closely linked in St. Gallen. Profit tax is levied annually on taxable income, while capital tax is levied on the company’s equity. Both are assessed based on the same tax return for juristic persons.
- The level and stability of equity can influence the company’s overall tax burden: higher equity increases capital tax, but may reduce thin-cap risks and related-party interest recharacterisation for profit tax.
- STAF-related reductions in the capital tax base for qualifying participations and IP can indirectly increase the relative importance of profit tax versus capital tax, especially for holding structures.
- For details on rates and base, see the St. Gallen capital tax page and the combined tax calculator.
Compliance Snapshot
This guide focuses on the substantive rules for corporate income tax in St. Gallen. For procedural aspects — who files, which forms to use and which deadlines apply — see the dedicated Forms & deadlines page.
| Area | Key points |
|---|---|
| Filing | Annual corporate tax return for juristic persons, usually via eTaxes-Unternehmen; paper submission remains binding. |
| Deadline | Ordinarily around six months after year-end; extensions commonly available on request (online within a standard window; beyond that by special request). |
| Documentation | Signed financial statements; profit-to-tax reconciliation; schedules for participation relief and special regimes; transfer pricing documentation where relevant. |
| Assessments & objections | Combined assessments for cantonal, communal and federal tax; objection rights and deadlines set out in the assessment notice. |
FAQs
How high is the corporate income tax rate in St. Gallen?
The cantonal profit tax for standard capital companies is based on a simple rate of 2.8% on taxable profit, increased by a communal surcharge expressed as a percentage of the simple cantonal tax. On top of this, companies pay direct federal corporate income tax at 8.5% of profit after tax (about 7.8% before tax). The combined effective rate depends on the company’s location and the applicable communal surcharge; see the Rates page or the official St. Gallen tax calculator for concrete examples.
What is the difference between profit tax and capital tax?
Profit tax is charged on the company’s taxable income for the year, while capital tax is charged on the company’s equity (share capital, reserves and hidden equity) at the end of the year. Both are levied annually and assessed together, but they operate on different tax bases and rates.
Are dividends from subsidiaries fully taxed in St. Gallen?
Qualifying participations can benefit from participation relief. This mechanism reduces the effective tax burden on net participation income (dividends and certain capital gains) based on a formula comparing participation income to total profit. Where the conditions are met, the effective St. Gallen and federal tax on qualifying dividends can be reduced significantly.
How are losses treated for St. Gallen corporate income tax?
Tax losses can generally be carried forward for up to seven years and offset against future taxable profits. There is no loss carryback. In restructurings or changes of ownership, special rules may limit the use of losses; advance tax rulings are often used where material loss carryforwards are involved.
Can I get a ruling on a planned structure or transaction?
Yes. St. Gallen, like other Swiss cantons, offers advance tax rulings. These are commonly used for holding and financing structures, IP arrangements, reorganisations, and application of STAF instruments. A well-prepared ruling request can provide valuable certainty on the corporate income tax treatment and its interaction with capital tax and federal tax.
Get St. Gallen business tax help (Sesch TaxRep GmbH) St. Gallen cantonal tax service