Side job in Switzerland: rules, contributions and dossier

The law does not generally prohibit secondary employment. But the duty of loyalty (Art. 321a CO) means that a side job must not impair the interests of the main employer – in particular no activity for a competitor.

Check in this order:

• Employment contract: does it contain a reporting obligation, a requirement of consent or an express prohibition?
• Competitive situation: are you working for a competitor or in an area where you use the main employer's know-how?
• Time burden: are recovery, performance and availability still guaranteed?

A side job that respects these points is as a rule permissible. Anyone who conceals it although the contract requires notification risks a warning through to dismissal.

The maximum working time under the Labour Act applies per employment relationship – not as a total across all jobs. That means: two positions of 40 hours a week each do not necessarily breach the Labour Act, but they may conflict with the employer's duty of care and with your health.

These limits are practically relevant:

• Night and Sunday work requires a permit and carries special surcharges.
• Rest periods between two work assignments must be observed – with two employers that is your responsibility.
• Excess hours in the main job may not be "offset" by a side job.

Anyone working 100 percent in the main job should realistically check whether a second job is sustainable in terms of time and health – not only legally.

Each employer settles AHV/IV/EO and unemployment insurance separately. In practice this leads to duplicate contributions that cannot always be offset – especially in occupational pension provision.

• AHV: contributions are deducted per employer; the contribution period counts in total.
• BVG: each employer applies the coordination deduction. With two part-time positions, the total insured amount can be too low – a well-known gap.
• Accident insurance: mandatory through both employers; non-occupational accidents are covered via the main employer.
• Daily sickness benefit: may be regulated differently by each employer.

Anyone with two positions totalling more than 100 percent should have the BVG situation reviewed once by the pension fund – not only at retirement age.

With several employers the rate determination principle applies: tax is calculated on the total income, but only the share is withheld by each employer. Anyone not subject to withholding tax declares both incomes in the tax return – that is not double taxation, but it can lead to a back payment.

Practical points:

• The second employer must be informed about the additional employment so that the tariff is applied correctly.
• With withholding-taxed employment, a subsequent ordinary assessment is possible if the income exceeds certain thresholds.
• Expenses and disbursements from the side job are only deductible if they are work-related and documented.

Not every side job belongs in the CV. The rule of thumb: include it when it is professionally relevant or explains a gap.

• Relevant: an activity that evidences your target competence – such as tutoring for prospective teachers, bookkeeping for a trust company, a barista job for applications in hospitality.
• Gap filler: a side job during a transitional phase explains a gap better than an empty line.
• Not relevant: purely casual work with no link to the target profession – here a collective entry is enough ("Various casual jobs, 2019–2021").

Careful with the wording: in the CV the side job must not appear more important than the main activity. List it under the main position, with reduced scope and a clear statement of the workload.

For third-country nationals, the work permit is as a rule tied to the employer and the position. A side job with another employer requires a new or amended permit – without it the activity is illegal, regardless of the employment contract.

For EU/EFTA nationals full freedom of movement applies; the reporting obligation when taking up a position remains, however. Anyone working on a self-employed basis on the side must also check registration with AHV as a self-employed person.

For cross-border commuters, the tax agreement with the country of residence must also be observed – a second employer in Switzerland can change the logic of withholding tax.