Guide 2026: tax return Switzerland - Canton of St. Gallen

Context

In brief

• Variable cantonal tax deadlines (St. Gallen: check with the cantonal administration)
• Federal/cantonal deductions for AVS/AI, LPP, LAMal and professional costs
• Online procedure via cantonal platform (available on the tax administration's website)
• Frontier: source tax withheld directly in Switzerland

Key facts

• What : Tax return 2026 (natural persons)
• When: Federal deadline 31 March 2026 (differentiated cantonal deadlines)
• Where: St. Gallen and national Switzerland
• Who: Federal/cantonal tax administration (AFC/ESTV and cantons)
• Key deductions: AVS/AI contributions (5.3%), LPP (7-18%), LAMal (CHF 300-2500 deductibles) The tax return in Switzerland for the period 2026 follows a federal-cantonal system. Residents in the canton of St. Gallen must respect both national regulations and local specificities. Direct federal tax and cantonal/municipal taxes are calculated separately. For frontier workers, the source tax is withheld directly by the Swiss employer, avoiding double taxation thanks to the 1976 Italian-Swiss Convention. #

Deadlines and procedures Deadlines for sending the declaration vary by canton. At the federal level, the deadline is March 31, 2026, but the canton of St. Gallen may have a specific extension. Taxpayers receive the forms from the cantonal tax administration. The + Taxpayer with health insurance (LAMal): must include in the tax return the exemption for LAMal health insurance (CHF 300-2500) + Taxpayer with professional costs: must include in the tax return the professional costs (e.g. travel, training) + Taxpayer with mortgage interest: must include in the tax return the mortgage interest (e.g. for property owners in Switzerland) The tax return in Switzerland for the period 2026 follows a federal-cantonal system. Residents in the canton of St. Gallen must respect both national regulations and local specificities. Direct federal tax and cantonal/municipal taxes are calculated separately. For frontier workers, the source tax is withheld directly by the Swiss employer, avoiding double taxation thanks to the 1976 Italian-Swiss Convention.

Operational details

Cantonal comparison: St. Gallen vs national media

The canton of St. Gallen has tax rates that are competitive with the Swiss average. While direct federal tax is uniform (2025 rate: 11.5% on taxable income), cantonal/municipal rates vary significantly.

Indicative Rates (2025)

• St. Gallen: Average cantonal rate ~12-14% (varies by municipality)
• National average: ~13-16% (Zurich: ~12%, Vaud: ~15%)

Deductions specific to St. Gallen

The canton of St. Gallen recognizes additional deductions for:

• Transport costs: Up to CHF 2,500 per year for commuters
• Childcare expenses: Up to CHF 10,000 per household
• Donations: To recognized organizations based in the canton

Impact of the New Frontier Agreement

The new border agreement (in force from 1 January 2024) introduces differentiated deductibles. For Article 9 of the Agreement, “old frontier workers” are people who met the tax requirements and worked in Graubünden, Ticino or Valais on 17 July 2023 or during the period from 31 December 2018 through 17 July 2023. Article 9 keeps covered employment income taxable exclusively at source in Switzerland; other workers follow the ordinary regime, with ordinary taxation in Italy, a credit for Swiss tax and Swiss withholding at 80% of the ordinary rates. The €10,000 figure in Article 4 of Italian Law No. 83/2023 is only the income limit referred to in Article 1(175) of Law No. 147/2013; it is not a general allowance for new frontier workers. Sources: ESTV factsheet (Italian) · Agreement, Art. 9 · Law No. 83/2023, Art. 4. Old cross-border workers remain taxed only in Switzerland (Art. 9 of the 2020 Agreement).

Concrete examples

A border worker resident in Italy with a Swiss gross income of CHF 120,000 in 2025 would have the tax withheld at source (hypothetical rate 15%). It could deduct CHF 6'360 (AVS/AI 5.3%) and CHF 9'600 (LPP 8%, example for 30-year-old), reducing taxable income to CHF 104'040. In Italy, it would apply the tax credit for

Useful planning tools

To estimate your pension strategy, use the pension planner and the pillar 3 simulator.

Key points

2026: Swiss Tax Declaration - Canton St. Gallen Guide

1. Document Collection

• Swiss salary certificate (with AVS/AI/LPP withholdings)
• Italian 730 model (for border workers)
• LAMal invoices and other deductible costs
• Documents for deducting transportation and childcare costs, such as:

+ Transportation cost documentation: train, bus, or highway ticket receipts, with a limit of CHF 400 per year. + Childcare cost documentation: receipts for childcare payments or other care activities, with a limit of CHF 2,000 per year.

2. Access to the Canton Platform

Register on the St. Gallen cantonal tax portal (link available on the official website). Use secure credentials provided by the administration. Note that access to the platform can also be made through the St. Gallen municipality online platform, where you can download the declaration models and consult the operational guides.

3. Guided Compilation

The system precompiles salary data and standard deductions. Verify and insert specific deductions (e.g., transportation, childcare). Note that the platform can also precompile data related to AVS/AI/LPP withholdings and pension contributions.

4. Sending and Confirmation

Send electronically by the cantonal deadline. Keep the transmission receipt. Note that the deadline for the 2026 declaration is March 31, 2027.

⚠️ Attention: Border workers must declare only non-Swiss-source income in Italy (e.g., Italian income). It is essential to consult Italian legislation to determine income subject to declaration in Italy.

Useful Tools

• Border Worker Tax Calculator to simulate net pay in the pay slip
• LAMal Guide to optimize health insurance
• Deduction Comparison Table to compare deductions between Swiss cantons and municipalities

Concrete Examples

Suppose we have a CHF 80,000 income and must declare Swiss and Italian income. Using the border worker tax calculator, we can estimate our net pay in the pay slip after the Swiss declaration.

Operational Checklist

• Verify the availability of necessary documents for the declaration
• Access the cantonal platform and complete the declaration
• Verify and insert specific deductions
• Send the declaration electronically by the deadline
• Keep the transmission receipt

Practical Scenarios Comparison

Suppose we have two practical scenarios: Scenario 1: We have no Italian income and must declare only in Switzerland. Scenario 2: We have Italian income and must declare in Italy and Switzerland. In the first scenario, we can use the cantonal platform to complete the declaration and send it by the deadline. In the second scenario, we must consult Italian legislation to determine income subject to declaration in Italy and use the cantonal platform to complete the Swiss declaration.

Regulatory References

• Federal Tax Act 1987 (LIF)
• Federal Tax Regulation 1992 (RIF)
• Cantonal Tax Legislation 2020 (NCIF)

Contacts

For assistance, contact the St. Gallen cantonal contributions administration (contact information on the official website).

Notes

• This guide is subject to changes and updates.
• It is essential to consult current legislation to determine specific requirements and deadlines.
• Tax declaration is a legal obligation for all Swiss residents.