Guide 2026: tax return Switzerland - Canton of St. Gallen (cross-border guide)

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. Border workers already active before 17 July 2023 maintain the exemption of €7,500, while new border workers benefit from €10,000. This transitional scheme (2024-2033) does not affect the 2026 return for 2025 income, already regulated by the old rules.

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

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