Reference checks in Switzerland: what employers can ask

Hiring decisions in Switzerland carry legal obligations that extend well beyond the interview room. When an employer contacts a candidate’s former supervisor or requests a written reference, the process sits at the intersection of employment law, personality rights, and data protection regulation. Swiss law does not prohibit reference checks, but it constrains them in ways that hiring managers and HR teams need to understand before picking up the phone.

The legal basis for reference checks in Switzerland

Swiss employment relationships are governed primarily by the Code of Obligations (Obligationenrecht, OR) and the Civil Code (Zivilgesetzbuch, ZGB). Two provisions are particularly relevant. Article 330a OR grants employees the right to a written employment certificate (Arbeitszeugnis) upon request, covering the nature and duration of the employment relationship as well as information on performance and conduct. Article 28 ZGB establishes general personality rights, which protect individuals from unlawful infringements on their personal sphere.

The revised Federal Act on Data Protection (revFADP), in force since September 2023, adds a further layer. It requires that personal data be processed lawfully, proportionately, and for a purpose that is evident to the data subject. Reference checks involve processing personal data — both the candidate’s and, indirectly, the referee’s — so the principles of transparency, purpose limitation, and data minimisation apply throughout.

What employers may ask

Swiss law permits employers to gather information that is relevant to the employment decision at hand. The guiding principle is proportionality: questions and requests must bear a reasonable relationship to the role being filled.

Permissible topics typically include:

Confirmation of employment dates and job title. Verifying that the candidate held the position they claim, for the period stated, is a standard and uncontroversial step.
Description of responsibilities and scope. Former employers may describe the tasks the candidate performed, the size of the team they managed, or the reporting structure they operated within.
Assessment of performance and conduct. The employment certificate under Article 330a OR explicitly covers performance and conduct, so asking a referee to elaborate on these areas is generally acceptable.
Reason for leaving the previous employment. This is commonly asked, though the former employer is not obligated to provide a detailed explanation. A factual statement — such as resignation, mutual agreement, or dismissal — is typically sufficient.
Rehire eligibility. Asking whether the former employer would hire the candidate again is a common practice and is generally considered permissible, though the referee is free to decline answering.

The key constraint is relevance. Questions that touch on the candidate’s professional history and suitability for the specific role fall within the legitimate scope of a reference check. Questions that stray into the candidate’s private life generally do not.

What is off-limits

Swiss personality rights and data protection law set clear boundaries on what may be asked during a reference check. Information that is not relevant to the employment decision, or that infringes the candidate’s personal sphere, is off-limits regardless of whether the referee would be willing to share it.

Topics that employers should not pursue include:

Health and medical history. Details about the candidate’s physical or mental health, sick leave patterns, or disability status are protected. The only narrow exception concerns health information that directly affects the candidate’s ability to perform the specific role, and even then, the inquiry should be directed at the candidate, not the referee.
Political opinions and trade union membership. These are aspects of personality that have no bearing on professional suitability in the overwhelming majority of roles.
Religious affiliation. Unless the role is within a religious institution, this is not a permissible topic.
Sexual orientation and private relationships. Information about the candidate’s personal life, marital status, or family planning is not relevant to a hiring decision and should not be solicited.
Criminal record. A candidate’s criminal history is accessible through an extract from the criminal record (Strafregisterauszug), which the candidate can obtain themselves. Employers should not ask referees for anecdotal information about criminal matters. For certain roles — particularly those involving financial responsibility or work with minors — requesting a formal extract from the candidate is the appropriate route.
Third-party personal data. Asking a referee to comment on other employees, or to share information that would reveal identifiable third parties, raises data protection concerns under the revFADP.

Even where a topic is not strictly prohibited, employers should consider whether the information is necessary for the decision. Collecting data that is merely interesting rather than decision-relevant creates unnecessary exposure under data protection principles.

Swiss law does not always require explicit consent before conducting a reference check, particularly when the candidate has themselves provided the referee’s contact details or listed them as a reference. However, obtaining the candidate’s written consent before contacting former employers is a widely recommended practice. It demonstrates transparency, aligns with the revFADP’s purpose-limitation principle, and reduces the risk of disputes.

Consent should specify which former employers may be contacted, the general scope of the inquiry, and the purpose of the data collection. If the employer intends to use a third-party screening provider, this should be disclosed as well.

Documentation standards

Documentation is where many reference-check processes fall short of legal expectations. Under the revFADP, employers must be able to demonstrate that personal data was processed lawfully and for a stated purpose. This requires maintaining records of what was asked, what was recorded, and how the information was used.

Practical documentation steps include:

Record the basis for the check. Note that the candidate consented, or that the referee was listed as a reference by the candidate.
Document the questions asked. Keep a record of the topics covered, ideally using a standardised questionnaire that is applied consistently across candidates for the same role.
Record the information received. Summarise the referee’s responses factually. Avoid recording subjective characterisations that are not supported by specific observations.
Note how the information was used. If the reference check influenced the hiring decision, record this. If it did not, record that as well.
Retain records for an appropriate period. Data should not be kept longer than necessary. Once the hiring decision is made and any challenge period has passed, records that are no longer needed should be deleted or archived in accordance with the employer’s data retention policy.

Candidates have a right under the revFADP to access personal data concerning them that the employer holds. Reference check notes are not exempt. Employers should therefore ensure that their records are factual, professional, and defensible.

Cross-border considerations

Switzerland is not an EU member state, but the revFADP was designed to ensure compatibility with the EU’s General Data Protection Regulation (GDPR). Where a reference check involves former employers in EU or EEA countries, the GDPR may apply to that portion of the processing. Employers conducting checks across borders should be aware that the applicable legal framework may shift depending on where the referee is located and where the data is stored.

For employers operating in the broader DACH region, the differences between Swiss, German, and Austrian requirements are manageable but real. German employment law, for instance, places strong emphasis on the reference’s duty to provide a truthful but benevolent assessment (wohlwollendes Zeugnis), while Swiss practice tends toward factual clarity. Understanding these nuances helps avoid misinterpretation of references obtained from different jurisdictions.

Practical recommendations

Employers conducting reference checks in Switzerland should adopt a structured approach:

Define the scope before contacting anyone. Determine which topics are relevant to the role and prepare a standardised set of questions.
Obtain candidate consent. Even where not strictly required, written consent reduces legal risk and builds trust.
Limit inquiries to professional relevance. Resist the temptation to ask open-ended questions that may lead referees into sharing protected information.
Use consistent documentation. Apply the same questionnaire and recording format to all candidates for a given role.
Train hiring managers. Those conducting reference calls should understand what they may and may not ask, and how to redirect a conversation that drifts into off-limits territory.
Engage screening support where complexity warrants it. For senior hires, regulated roles, or cross-border checks, a structured screening process can help maintain consistency and documentation standards.

Conclusion

Reference checks are a valuable tool for Swiss employers, but they operate within a defined legal framework. The distinction between permissible and off-limits questions turns on relevance, proportionality, and respect for personality rights. Documentation is not an afterthought — it is a legal requirement under the revFADP and a practical safeguard against disputes. Employers that approach reference checks with structure and discipline can gather meaningful information without exposing themselves to unnecessary legal risk.

This article provides general information and does not constitute legal advice in individual cases.