Tax return in the canton of Zug

Who is required to file a tax return in the Canton of Zug?

In principle, anyone who resided in the Canton of Zug on December 31 of the tax year is liable for tax. This also applies to individuals with economic ties to the canton, such as those who live outside the canton but own property or a business establishment here.

Married couples who are legally and effectively living together file a joint tax return, regardless of their matrimonial property regime. In the event of separation, divorce, or the death of a spouse during the tax year, each person must file their own return.

Deadlines and extensions

The 2026 tax return in the Canton of Zug must be submitted by April 30, 2027 . The documents will be sent out starting at the end of February 2027.

Extensions are generally granted until December 31, 2027, and can be requested online. Requests for extensions beyond this date must be submitted in writing to the tax administration with a valid justification.

Important in all cantons: The request must be made before the standard deadline expires. Extensions cannot be granted retroactively, and reminder deadlines are generally non-extendable. If you neither file nor request an extension, you will first receive a reminder with a fee, followed by an assessment based on the tax authority's discretion—which is usually to your disadvantage—plus a fine.

Good to know in the Canton of Zug

• Zug has one of the latest standard filing deadlines in Switzerland—about a month later than the Canton of Zurich.
• Since the 2024 tax year, the securities register must be completed, even if no withholding tax is being reclaimed.
• Zug is considered the most tax-favorable canton in Switzerland. However, this does not change the obligation to declare: all income and assets must be fully disclosed.

Withholding tax: When you still need to file a tax return

If you work in Switzerland with a B or L residence permit, your taxes are usually paid directly via payroll deduction. However, this does not always settle the matter. Federal law determines when an ordinary tax return is additionally required, meaning the system is the same in all cantons.

Mandatory, without the option to choose

• Gross income of CHF 120,000 or more per calendar year from employment. For married couples, incomes are not combined for this threshold—the limit applies per person. In this case, the tax authority will proactively contact you and send you a tax return.
• Income not subject to withholding tax, or taxable assets – such as from self-employed side jobs, securities, real estate, pensions, or alimony. The authorities will not take action automatically here: you must request the tax return yourself by March 31, 2027.

The second point is the most common pitfall. The CHF 120,000 threshold is set by federal law and applies uniformly everywhere. In contrast, the thresholds for side income and assets are determined by the cantons themselves – about half do not publish them at all and decide on a case-by-case basis. If you have side income or significant assets, it is better to clarify this proactively than to wait for someone to contact you.

Voluntary filing is often worth it

If you are below the thresholds, you can apply for a subsequent ordinary assessment. This treats you the same as individuals subject to ordinary assessment and allows you to claim deductions that are not included in the withholding tax rate or are only included as a flat rate:

• Pension fund buy-ins
• Contributions to Pillar 3a
• actual professional expenses, including weekly residency costs
• self-funded education and training costs – up to CHF 13,000 per year for direct federal tax
• Third-party childcare costs
• Medical and disability expenses as well as interest on debt

Residence abroad: Quasi-residency

If you live abroad and work in Switzerland, you can also apply for a subsequent ordinary assessment, provided that at least 90% of your worldwide income is taxable in Switzerland, with your spouse's income included in this calculation. In this case, the application must be submitted anew each year.

The deadline is strict

The application must be submitted by March 31, 2027 . This is a preclusive deadline and cannot be extended. If you miss it, you will remain subject to withholding tax for that tax period. If you leave Switzerland, the deadline ends as soon as you deregister with the municipality.

Conversely, once an application is submitted, it cannot be withdrawn. Anyone who fails to file a tax return after a reminder will be assessed at the discretion of the authorities and risks a fine. Once you are subject to mandatory subsequent assessment, you will generally remain in the ordinary procedure until your withholding tax obligation ends.

If you switch to a C permit or marry a person with Swiss citizenship or a C permit, your withholding tax obligation ends anyway – you will be subject to ordinary assessment starting the following month.

The most important deductions

Cantonal and federal authorities often have different maximum limits for the same tax deductions. This is exactly where the most common mistakes occur – and where the most money is left on the table. These items are almost always worth checking:

• Professional expenses – commuting costs, meals away from home, other professional expenses, and home office portions. The limits for these vary between the cantons and the federal government.
• Pillar 3a – the maximum amount is set by the federal government and applies equally in all cantons. What matters is whether you are enrolled in a pension fund.
• Pension fund buy-ins – fully deductible and usually the single biggest lever. Note the three-year waiting period for capital withdrawals.
• Childcare costs – daycare, after-school care, and childminders. The requirement is that the care is necessary due to employment, education, or incapacity to work.
• Insurance premiums and savings interest – a flat-rate deduction that increases if neither you nor your employer have made contributions to the 2nd pillar or pillar 3a.
• Medical and accident expenses – deductible to the extent that they exceed a percentage-based deductible of your net income.
• Further education and retraining – for direct federal tax, up to a maximum of CHF 13,000 per year, provided there is a professional connection.
• Property maintenance – either actual costs or a flat rate. It is worth comparing the two every year, as you are free to choose.
• Donations to charitable organizations – deductible up to a percentage of taxable income, provided the organization is tax-exempt.
• Interest on debt – particularly mortgage interest, within the statutory limits.

For wealth tax purposes, the personal deduction and the maximum rental deduction are adjusted for inflation.

Childcare costs are subject to different limits at the cantonal and federal levels – for direct federal tax, the maximum deduction is CHF 25,800 per child.

iqtax checks your situation against current cantonal and federal rates and points out deductions that may apply to you.

Which documents you need

You don't need to submit every single receipt – but anything you want to claim must be verifiable. Rule of thumb: include the receipt for larger amounts; for smaller items, a precise description in your tax return is sufficient. You should keep everything until your tax assessment is final.

Mandatory documents

• Salary statement from all employers during the tax period – without exception.
• Pillar 3a certificate, if you are claiming a deduction.
• Confirmation of pension fund buy-ins, if you have made contributions.
• Tax statement or bank portfolio summary for securities, including balance and income as of December 31.
• Receipts for medical and disability expenses, if you are declaring them – including statements from your health insurance provider.
• Maintenance receipts and annual mortgage statement for home ownership.
• Childcare invoices for third-party childcare costs.
• Donation receipts for larger amounts.

Also useful

• Bank statements as of Dec 31st showing the balance and interest income for all accounts
• Receipts for professional expenses and continuing education costs
• Annual summary of cryptocurrencies with holdings as of Dec 31st
• Statement of the renovation fund for condominiums
• Receipts for alimony, support payments, and inheritances
• Proof of enrollment for adult children in education

You don't need to know this by heart.

After onboarding, iqtax creates a personalized, smart checklist for you. It shows at a glance which documents are required for your situation, which ones you have already uploaded, and what is still missing. If anything is missing, we will actively notify you – ensuring your tax return is complete before it is submitted.

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