Moved to Switzerland Mid-Year? Preparing Your First Swiss Tax Return

First check whether you need to file a return

Moving to Switzerland during the year does not, by itself, tell you whether you must submit a tax return. Establish your tax residence, then your filing route. This guide covers a move from abroad to Swiss residence, with Basel-Stadt examples. Moving between Swiss cantons follows different rules.

Residents in the ordinary assessment system generally file a return. Many foreign employees without a C permit instead have tax deducted from salary through Quellensteuer. Basel-Stadt's English tax-return guide expressly distinguishes people subject only to withholding tax.

Withholding does not always settle everything. A subsequent ordinary assessment, known as NOV, may be compulsory or requested voluntarily. In Basel-Stadt, the gross employment-income threshold is at least CHF 120,000 for one person; the rules adjust the calculation for a partial tax year. See the Basel-Stadt tax ordinance, sections 82a–82b. Income or assets outside payroll can also trigger compulsory NOV, as the 2026 cantonal withholding-tax guide explains. Our B-permit and tax-at-source guide covers this decision in more detail.

A voluntary NOV application is generally due by 31 March following the tax year. This deadline cannot be extended, and the resulting assessment can produce either a refund or an additional bill. The Federal Tax Administration's withholding-tax guidance explains that NOV continues in subsequent years while withholding-tax liability continues. Check the consequences before applying.

Build a timeline before entering income

Write down when you left your former home, established Swiss residence, started employment and received any exceptional payments. Keep registration confirmations, employment contracts and evidence of any period when you maintained homes in two countries. Your first working day and your tax-residence start date are not necessarily identical.

For a move from abroad to Basel-Stadt, the ordinary return generally covers income from the start of Swiss tax liability to year-end. The canton explains this in its guidance on arrivals from abroad. A salary earned before the move is not automatically Swiss-taxable simply because it appears on a full-year foreign certificate.

Keep pre-arrival amounts separately identifiable. Swiss work before relocation, overlapping residence, a delayed bonus or share awards connected with work in several countries may need a closer allocation review. Avoid copying a foreign annual income total into the Swiss return without checking what period and payments it includes.

Understand why the tax rate may use a higher income

For a partial year, recurring income such as salary is generally converted to an annual equivalent to determine the tax rate. That rate is then applied to the relevant taxable income for the Swiss period. Annualisation does not mean that Switzerland has taxed twelve months of salary. The Federal Tax Administration's guide for new taxpayers explains this distinction.

A simple illustration

Assume someone becomes Swiss-resident on 1 July and earns a regular CHF 6,000 a month from July to December. The six-month salary is CHF 36,000. Before deductions and other adjustments, the annual equivalent used to determine the rate is CHF 72,000. The example illustrates the calculation method; it is not an estimate of the final tax bill.

Non-recurring income is not automatically multiplied in the same way. Federal guidance distinguishes recurring income from non-recurring receipts, which are generally included without annualising them for the rate. Some payments have separate rules. Use the payment's actual character and earning period, rather than treating every amount described as a “bonus” alike. See the 2026 federal tax-return guidance on partial-year liability.

Prepare a worldwide asset snapshot

For someone who remains resident through year-end, the relevant asset date is normally 31 December. If Swiss tax liability ends earlier, the relevant date can be the end of that liability. Collect balances and valuations for accounts, investments and other reportable assets worldwide, together with outstanding debts. An account does not become irrelevant because it stayed abroad.

Basel-Stadt prorates wealth tax for the duration of partial-year liability. Declare the relevant full asset values and residence period; do not reduce every bank balance yourself to reflect the months spent in Switzerland. Foreign real estate and businesses require separate allocation and can affect the rate even where their value is exempt from Swiss taxation. The Basel-Stadt 2025 tax guide covers these principles.

Use our foreign income and assets guide for the records to gather. Foreign-property, business and other complex cross-border work should be reviewed and quoted separately before preparation begins.

Put the first-year file in order

• Residence: your arrival date, previous address, permit and any tax-office correspondence.
• Employment: Swiss salary certificates, payslips showing withholding tax, and foreign statements with periods clearly marked.
• Investments: year-end balances plus transaction and income statements that separate payments before and after arrival.
• Deductions: pension contribution certificates and evidence of relevant costs, with payment dates.
• Open questions: a short list of bonuses, pensions, share awards or property income that needs allocation.

Request missing statements early. Label each document with its country and period so a preparer can follow the move without reconstructing it from a stack of annual certificates.

Two common first-year questions

Can I simply divide every annual figure by twelve?

No. Identify the actual income falling within the relevant period and keep the rate calculation separate. Asset values use a valuation date, and individual deductions have their own rules.

I paid tax through payroll. Can I ignore a tax-return letter?

No. Check why it was issued and confirm the filing requirement with the canton if unclear. Under NOV, payroll tax is credited against the ordinary assessment; it does not replace the requested return.

Official sources

Checked on 29 September 2026.

• Basel-Stadt 2025 tax-return guide
• Basel-Stadt tax ordinance: NOV requirements
• Federal Tax Administration: withholding tax and NOV
• Federal guide for new taxpayers
• Federal 2026 tax-return guidance: partial-year liability