Germany–Switzerland · Article 15a of the Tax Treaty

Non-Return Days for Frontier Workers Between Germany and Switzerland

The number of work-related days on which an employee does not return home can determine whether they continue to qualify as a frontier worker under Article 15a of the Germany–Switzerland double taxation agreement. For full-year employment, up to 60 relevant non-return days are generally permitted. Exceeding the applicable limit can fundamentally change the taxation of Swiss employment income.

Article 15a(2) of the Tax Treaty

Occasional overnight stays away from home do not automatically end frontier-worker status

A frontier worker is generally a person who is resident in one contracting state, has their workplace in the other contracting state and regularly returns home.

The treaty does not require an employee to return home every day without exception. For full-year employment, the non-return-day rule causes frontier-worker status to be lost only if the employee does not return home for work-related reasons on more than 60 working days. The other eligibility conditions must also be met.

The relevant measure is therefore not every night spent away from the German home, but only work-related non-return days that count under the treaty rules.

The Key Threshold

60 non-return days for full-year employment

60 permitted non-return days

An employee working in the other contracting state throughout the calendar year may generally have up to 60 work-related non-return days without losing frontier-worker status for that reason alone.

Frontier-worker status is lost under the non-return-day rule only when the applicable limit is exceeded.

Definition

When does a day count as a relevant non-return day?

A non-return day generally requires the employee actually to remain away from home after finishing work on a working day, with the failure to return being caused by their work.

JOB

Work-related reason

The failure to return home must be connected with the employee’s work. Typical situations may include business trips lasting several days, overnight stays required for work or particular assignments.

NIGHT

Actual failure to return

It is not enough that returning home would theoretically have been unreasonable. The employee must actually have remained away from home.

DAY

Working day

The starting point is generally the working days agreed in the employment contract. An absence from home does not automatically qualify as a non-return day.

The Crucial Distinction

Private overnight stays generally do not count as work-related non-return days

If a frontier worker stays away from their German home for private reasons, the required connection with their work is generally absent.

Every night spent away from the German home should therefore not automatically be included in the list used for the 60-day rule.

Record work-related overnight stays separately
Distinguish private stays from work-related stays
Document business travel
Record the work location for each day
Document where the employee stayed overnight
Record the reason for not returning home

Work-Related Reasons

A day may also qualify if returning home after work is unreasonable

Under the interpretation agreed between Germany and Switzerland, a failure to return home may qualify as work-related where returning home is impossible or unreasonable for professional reasons.

When travelling by car, returning home after work is considered unreasonable in particular if the shortest road distance exceeds 100 kilometres each way.

When using public transport, returning home may be unreasonable in particular if the fastest connection at normal commuting times takes more than 1.5 hours each way.

Distance & Travel Time

Guidelines for assessing whether a daily return home is reasonable

>100 km

Travelling by car

If the shortest one-way road distance exceeds 100 kilometres, returning home after work may in particular be regarded as unreasonable.

>1.5 h

Public transport

If the fastest one-way connection at normal commuting times takes more than 1.5 hours, this may likewise indicate that returning home is unreasonable.

Shift Work & On-Call Duties

Work extending over several calendar days does not automatically prevent frontier-worker status

Operational requirements may cause a period of work to extend over several calendar days, particularly for shift workers, hospital staff, employees on call and similar occupations.

Such working arrangements do not in themselves prevent a regular return home under Article 15a. Returning home after the end of a continuous work period may satisfy the return requirement; each calendar day crossed by a shift is not automatically a non-return day.

In these cases, it is particularly important to document the start and end of each shift, the work location and any overnight stays.

Working from Home

A full day worked at the German home is not a non-return day

Where a frontier worker resident in Germany spends the entire working day working at their German home, there is no work-related failure to return home after finishing work.

Full days worked at home therefore generally do not count towards the 60-day limit. The regular-return requirement remains separate: from 2026, the employee must travel from home to the Swiss workplace and back on at least 20% of the contractually agreed working days in the calendar year.

A full day worked at the German home ≠ a non-return day
Continue to document the work location
Record home-working days separately from days worked in Switzerland
Review the tax consequences separately
Review social security separately
Keep home-working days separate from the non-return-day count

Employment for Part of the Year

Starting or ending employment during the year does not automatically allow the full 60 days

If an employee is not employed in the other contracting state throughout the calendar year, the permitted number of non-return days is reduced proportionately.

The allowance is generally five non-return days for each full month of employment and one day for each full remaining week. The same period must not be counted twice.

The resulting individual limit applies to the relevant period of employment.

Employment arrangement	General rule	Consequence
Full-year employment	60 days	Up to 60 relevant non-return days are generally permitted.
Full months of employment	5 days per full month	Reduce the individual annual limit accordingly.
Additional full weeks	1 day per full remaining week	Include weeks not already counted within the full months.
Part-time work on every normal working day	Generally 60 days for a full year	Reducing daily working hours alone does not automatically reduce the 60-day limit.
Part-time work on only some days of the week	Proportionate reduction	Reduce the permitted number of days in proportion to the agreed working days.

Part-Time Work

Not every part-time arrangement reduces the limit below 60 days

If a part-time employee works fewer hours but generally works on every normal working day in the other state, the allowance remains 60 non-return days for full-year employment.

The position differs where part-time work is performed on fewer days, for example three rather than five days per week.

In these cases, the permitted number of non-return days is generally reduced in proportion to the contractually agreed working days compared with normal full-time working days. Days worked at home should not be confused with days off under a part-time arrangement.

Documentation

Keep an ongoing record of non-return days throughout the year

Record working days

For each relevant day, record whether the employee worked and where the work was performed.

Document overnight locations

Where the employee does not return home, record where they actually spent the night.

Record the work-related reason

Identify the specific reason, such as a business trip, on-call duty, an assignment lasting several days or another work-related circumstance.

Retain supporting documents

Travel expense claims, hotel invoices, work schedules, calendars and employer records can support the non-return-day count.

Prepare an itemised schedule

If non-return days affect frontier-worker status, a clear, itemised schedule of travel days is particularly important.

Reconcile the employer’s certificate

If frontier-worker status is lost, check that the employer’s certificate of non-return days is consistent with the tax records.

Supporting Evidence

Typical documents for reviewing the 60-day rule

CAL

Calendar

Record working days, home-working days, holidays, business trips and overnight stays as promptly as possible.

HOTEL

Hotel invoices

Hotel invoices can document work-related overnight stays away from the German home.

TRIP

Travel expense claims

Employer travel expense records can establish the work-related reason for not returning home.

SHIFT

Duty rosters and shift schedules

For shift work or on-call duties, schedules are important evidence of working hours and work patterns.

GRE

Frontier-worker forms

The certificate of residence and, where applicable, the employer’s certificate should be consistent with the other tax documents.

LIST

Travel-day schedule

An itemised schedule showing the date, work location, overnight location and reason for not returning home makes the review considerably easier.

Exceeding the Limit

More than 60 relevant non-return days can fundamentally change the taxation of employment income

If the employee exceeds their applicable limit, the special frontier-worker status under Article 15a generally ceases to apply for the tax year concerned.

The employment income must then be assessed under the treaty’s general employment income rules. The country where the work is performed and the actual workdays can consequently become much more important in allocating taxing rights.

Article 15a no longer applies as the frontier-worker rule
Review the general employment income rule in Article 15
Allocate workdays between countries
Reassess the Swiss tax treatment
Adjust the German income tax return
Coordinate withholding tax and double taxation relief

Why the Threshold Matters

The 61st relevant day can matter more than the 60th

The 60-day rule does not mean that only the days above the threshold receive different tax treatment. Exceeding the applicable limit can instead cause frontier-worker status to be lost for the year as a whole.

An employee with a high number of work-related overnight stays should therefore review whether the frontier-worker rule still applies before the year has ended.

If the employee is likely to approach the limit, it may be useful to model the expected German and Swiss tax consequences during the year.

Typical Situations

Days that often require closer examination

Situation	Non-return day?	Points to consider
Work-related overnight stay in Switzerland	Potentially	Document the work-related reason and the actual failure to return home.
Business trip lasting several days	Potentially	Document the working days and individual stages of the trip.
Private overnight stay with friends	Generally no	The required connection with the employee’s work is generally absent.
Full day worked at the German home	No	The employee is already at home.
Long journey combined with an actual overnight stay	Potentially	Check whether returning home was unreasonable and whether the employee actually remained away.
Holiday in Switzerland	Generally no	This is not a work-related non-return day.
Overnight on-call duty	Requires review	Check the continuous work period and the return after it ends; document the duty roster.

Common Mistakes

Frequent errors when counting non-return days

Counting every night spent in Switzerland

Private overnight stays do not automatically qualify as work-related non-return days.

Treating home working as a failure to return

A full day worked at the German home does not involve a failure to return home after work.

Always using a limit of 60 days

A lower individual limit may apply to employment covering only part of the year or to part-time work involving fewer working days.

Failing to collect evidence

A list prepared retrospectively without verifiable travel and employer records can create difficulties in substantiating the days.

Looking only at the overnight stay

It is also essential to establish whether the failure to return home was actually caused by the employee’s work.

Not noticing an excess until the tax return is prepared

Swiss withholding tax and the German tax assessment may then already have been based on an incorrect assumption during the year.

Non-return days for frontier workers in Switzerland

What is a non-return day for a frontier worker?

A relevant non-return day generally arises when an employee actually remains away from home after finishing work on a working day and the failure to return is caused by their work.

How many non-return days are permitted?

For employment throughout the calendar year, up to 60 relevant non-return days are generally permitted. The limit must be reduced for employment covering only part of the year and for certain part-time arrangements involving fewer working days.

What happens on the 61st non-return day?

For full-year employment, more than 60 relevant non-return days can cause frontier-worker status under Article 15a to be lost. The treaty’s general employment income rules must then generally be applied.

Does a private overnight stay in Switzerland count as a non-return day?

Generally not for that reason alone. For the 60-day rule, the failure to return home must be caused by the employee’s work. Private reasons must therefore be distinguished from work-related reasons.

Does a day worked from home in Germany count as a non-return day?

No. A working day spent entirely at the home in the country of residence generally does not count as a non-return day under Article 15a. The separate regular-return requirement must nevertheless be met.

When is a daily return home considered unreasonable?

For travel by car, returning home may be unreasonable in particular where the shortest one-way road distance exceeds 100 kilometres. For public transport, this applies in particular where the fastest one-way connection at normal commuting times takes more than 1.5 hours. The employee must also actually have remained away from home.

How is the limit calculated if employment starts during the year?

For employment covering only part of the year, the limit is reduced proportionately. The allowance is generally five days for each full month of employment and one day for each full remaining week, without counting the same period twice.

Is the 60-day limit always reduced for part-time work?

No. If a part-time employee simply works fewer hours on every normal working day, the limit generally remains 60 days for full-year employment. If they work on fewer days, the limit is generally reduced in proportion to the agreed working days.

Which documents should I retain to support non-return days?

Useful records include calendars and workday schedules, hotel invoices, travel expense claims, business travel documents and shift schedules, together with an itemised schedule showing the date, work location, overnight location and work-related reason.

How does the tax treatment change if frontier-worker status is lost?

The taxation of employment income generally ceases to follow the special frontier-worker rule in Article 15a. Instead, the general rules in Article 15 must be considered in particular. Actual workdays in Germany, Switzerland and any third countries can then be decisive in allocating taxing rights.

Germany–Switzerland Tax Advice

Approaching the 60-day limit or unsure which days count?

We review non-return days under Article 15a, the individual limit, home-working and business travel days, and the consequences of a possible loss of frontier-worker status, and coordinate the German and Swiss tax treatment.

Arrange an Initial Consultation