Individuals

September 21, 2026

Joint Taxation of Spouses with Separate Residences at the Cantonal and International Levels

Modern family structures and increasing mobility in the workplace can lead to spouses living in different locations. This gives rise to complex tax issues. In this workshop, you will learn about various scenarios involving family taxation in intercantonal and international contexts, using real-world examples.

all solutions from this seminar

Julia von Ah

Ramon Lisci

Note: This language version is an automatically generated translation. The text may therefore contain linguistic and terminological errors.

view in original language (German)

Case 1: Single-income family in a married couple living apart but still legally married, with residences in different municipalities, cantons, and countries

1. Facts of the Case

1.1 Basic Facts—Intermunicipal

A married couple, both Swiss citizens, have eight children together. Due to space constraints—they are unable to find a suitable apartment for their large family—the wife moves with the four youngest children into an apartment in the municipality of X, Canton of Zug. The father remains in the apartment in the municipality of Y, Canton of Zug, with the four older children. Although the family is physically separated, the spouses remain committed to their marriage. The father, the sole breadwinner, holds a leadership position at an international corporation.

Question

How is the intermunicipal tax allocation calculated?

1.2 Option 1 – Intercantonal

Same facts as in the basic scenario. Additionally: As part of his employment, the husband receives, among other things, carried interest. Preliminary rulings and information are available regarding the Swiss tax and social security implications (taxation of the carried interest at the place of residence and no social security coverage). Due to their living situation, the family has now decided that the wife will move with the four younger children to Municipality C in the canton of Lucerne.

Question

How is the intercantonal tax allocation determined?

1.3 Scenario 2 – International

Same facts as Variant 1. Due to their living arrangements, the family has now decided that the wife will move abroad with the four younger children.

Question

How is the international tax allocation determined?

Case 2: Dual-income spouses with separate residences—intercantonal

2. Facts

2.1 Basic Facts—Residences in ZH and AG

After completing his studies, C. (husband) founded a successful startup, which now comprises several operating corporations held by a holding company.

C. and V. (wife) have been married for one year. C. lives (in his own home) and works in the canton of Zurich. V. lives (in her own home) and works in the canton of Aargau. C. holds a 40% stake in the holding company. The wealth tax value of the 40% stake is CHF 20 million. C. receives annual dividend payments of CHF 500,000 from the holding company.

Question

How is the intercantonal tax allocation determined?

2.2 Variant 1 – Residences in ZH and GR

Same facts as in the basic scenario, with one change: V. (wife) lives (in her own home) and works in the canton of Graubünden (Chur).

Question

How is the intercantonal tax allocation determined?

Case 3: Dual-income married couple with separate residences—international

3. Facts

3.1 Basic Facts—Dual-Income Couple

A few years later.

C. and V. are still married and living together. C. (husband) works (as an employee) and still lives in the canton of Zurich. V. (wife) has been living and working (as an employee) in Germany for several years. Both spouses live in their own homes (each as sole owner). The couple usually meets on weekends, alternating between his and her place of residence. The spouses have agreed to separate property. V. has granted C. an interest-free loan of CHF 1 million. C. has taken out a mortgage on his property in the canton of Zurich. C. is also the sole owner of a vacation home in Spain.

Questions

How is C.’s income and assets taxed in Switzerland?
In particular: How are the two debts and the interest on them taken into account for C.?

3.2 Scenario 1 – Parents, Single-Income Household

A short time later.

C. and V. are now becoming parents and decide to maintain separate residences for the time being. V. remains at her residence in Germany with their child. C. demonstrably provides financial support for the entire family.

Question

How is C.’s income and wealth taxed in Switzerland?

3.3 Scenario 2 – Parenting, Single-Income Household – Wife Residing in a Third World Country

Same facts as Scenario 1. However, V. (the wife) lives with their child in a developing country.

Question

Is there any difference compared to the approach taken in Scenario 1?

3.4 Scenario 3 – Dual-Income Household, with the Foreign Spouse Having Limited Tax Liability in Switzerland

Same facts as in the base scenario; however, V. has additionally purchased a property in the canton of Zurich, financed with a bank loan.

Question

How are C. and V. taxed in Switzerland?

Case 4: New Marriage in Switzerland—Child Support Payments Abroad for Children from a Previous Marriage

4. Facts

4.1 Basic Facts

Many years later.

C. had since emigrated to Germany. C. and V.’s second child was born. Then C. and V. divorced. Two years ago, following his divorce from his then-wife V., C. moved to Switzerland. Today (in 2023), he lives and works in the canton of Zurich. He has been married for the second time since June 2022 to his wife, Z., who currently lives in Spain for professional reasons. He pays child support for his children from his first marriage, who live with their mother in Germany. The older child (X.) is 21 years old and is studying in Germany. He provides CHF 1,000 per month in support for this child. The younger child (Y.) is 15 years old, still attends school, and receives CHF 500 per month; both child support payments were agreed upon in the divorce decree.

Question

To what extent can C. claim the child support expenses in Switzerland?

4.2 Variant 1

Same facts as in the basic scenario, except that C. voluntarily transfers CHF 1,000 per month to his ex-wife for the younger child’s support (the transfer is made as a lump sum with the note: Child support, including additional amount for child Y.), which is CHF 500 more than was agreed upon in the divorce decree.

Question

Can C. claim the voluntary child support payment as a deduction in Switzerland?

4.3 Variant 2

Same facts as in the basic scenario, except that C. transfers only CHF 500 (instead of CHF 1,000) per month in child support to the older (adult) child.

Question

Can C. claim the reduced child support payments as a deduction in Switzerland?

Case 5: Joint or Separate Tax Assessment

5. Facts

Z. has since moved to Switzerland—into C.’s apartment—and has been working in a job in Switzerland ever since. Living together proved to be difficult. On April 2, 2026, C. and Z. signed a separation agreement that retroactively establishes their separation as of July 31, 2025, for an indefinite period. C. received an additional variable salary payment of CHF 500,000 as of July 15, 2025. As of September 30, 2025, C. retroactively deregistered from the shared family residence in the Canton of Zurich and moved to the Principality of Liechtenstein on October 10, 2025. Ms. Z. continues to live in the shared family home. Upon moving out of the home, C. will transfer the balance of the joint household account, amounting to CHF 20,000, to Z. In the separation agreement, C. and Z. agreed that, instead of making spousal support payments to Z., C. would pay a lump-sum payment of CHF 100,000, to be paid in two equal installments in 2026 and 2027. In a notice sent on February 23, 2026, C. was requested to file his own tax return for the calendar year 2025. C. does not agree that he is required to file a separate tax return for the 2025 tax year in the Canton of Zurich.

Questions

What is the legal situation regarding the tax assessment for the 2025 tax year?
How should the capital payment to Z., to be paid in two installments, be taxed in the tax years 2026 and 2027?