What Art. 330a CO requires of a reference letter
Entitlement, content, form and limits of the Swiss reference letter — explained clearly, including the points where practice and doctrine diverge.
- Mandatory parts of the full letter
- Benevolence vs. truthfulness
- Right to correction + limitation period
Key facts on Art. 330a CO
Art. 330a CO is the central norm for the reference letter in Swiss labour law — concisely worded, broadly interpreted in practice.
- Legal basis
- Art. 330a Code of Obligations (CO)
- Who is entitled
- Every employee
- Form
- In writing, hand-signed or electronically signed
- Issuance period
- On request at any time; at the latest at the end of employment
- Limitation period
- 10 years (Art. 127 CO)
- Correction
- Right to correction if the content is incorrect
The wording — and what it means
Art. 330a para. 1 CO essentially reads: the employee may at any time request a reference letter from the employer that sets out the type and duration of the employment relationship as well as performance and conduct. Para. 2 adds: at the employee's specific request, the letter is to be limited to type and duration of employment (= employment confirmation).
What sounds neutral has substantial consequences. First: the right is not tied to a specific contract type or duration. Fixed-term internships, casual roles and part-time relationships also create the entitlement. Second: the letter must describe the person fairly — not concealing weaknesses, but not deliberately hampering their career either. This dual duty — benevolent and truthful — is the actual core of practical disputes.
Mandatory parts of the full letter
A qualified full letter without these elements is incomplete — and the employee can demand it be amended.
Personal details
First and last name, date of birth or another unambiguous identifier that establishes the person's identity beyond doubt.
Duration of employment
Start and end date. With multiple roles or contracts, the total duration plus, if applicable, the respective sub-periods.
Role and area of responsibility
The official job title plus a concrete description of the activities performed and responsibilities — not just bullet points.
Performance assessment (full letter)
Assessment of professional performance, way of working, resilience and successes. Tied to observable behaviour, not blanket judgements.
Conduct assessment (full letter)
Assessment of conduct towards superiors, colleagues and, where applicable, clients — factual, free of discriminatory hints.
Closing formula
Reason for ending (where the person agrees or it is necessary for understanding), thanks, good wishes for the further career path.
The four guiding principles
Benevolence
The letter must not unduly hinder the person's career progress. Negative facts are mentioned only if essential to the overall picture.
Truthfulness
At the same time the letter must be truthful. Embellished letters can make the issuing employer liable — and harm the next employer.
Completeness (full letter)
In a qualified full letter, essential aspects must not be omitted. If the conduct assessment is missing, that is conspicuous — and problematic.
Clarity
The letter must be understandable to third parties. Hidden codes, ambiguous wording and double meanings violate the requirement of clarity.
Benevolence vs. truthfulness — how to resolve?
A classic tension: an employee delivered well technically but was difficult in the team. The letter must neither dramatise the difficulties nor conceal them. Approaches recognised in doctrine and case law:
- Describe observable behaviour, do not moralise. Instead of "difficult in the team" → name concretely what was actually observed.
- Choose the weighting: what was essential for the role? If the position was predominantly technical, conduct may be shorter — but not entirely absent.
- Avoid double meanings: a wording that industry insiders read differently than the affected person violates the requirement of clarity.
- Use interim letters: a well-drafted interim letter prevents the final letter from becoming the conflict arena.
Right to correction
If the reference letter is incorrect from the affected person's perspective, there is a right to correction. In practice this means: the person identifies precisely which passages they object to, and the employer must be able to substantiate the assessment factually. Without evidence, the employer's position in court is weak — keyword: documentation from review meetings, target achievements, recorded incidents.
What is contested in practice is rarely the wording, but whether a particular qualitative assessment is tenable. This is exactly where a structured process like ZeugnisPilot helps: the compliance check flags formulations that typically trigger disputes and proposes substantiable alternatives.
What Art. 330a CO does not regulate
- No fixed deadline for issuance — doctrine requires "appropriate", practice thinks in days to a few weeks.
- No obligation to use codes: on the contrary — codes contradict the requirement of clarity.
- No right to a particular "grade": the assessment must be factual and provable, not expressed in a fixed grading system.
- No waiver possible: the entitlement protects the employee; an agreement to waive the letter entirely is void.
Frequently asked questions about Art. 330a CO
Is every employee entitled to a reference letter?
What is the difference between a full letter and an employment confirmation?
How quickly must the reference letter be issued?
What if the letter is incorrect from the employee's perspective?
May "hidden codes" be used?
How long is the limitation period?
What about the reason for ending?
May the letter mention illness or pregnancy?
An interim letter — when is there an entitlement?
Compliant with CO 330a by default
ZeugnisPilot automatically checks every letter against Art. 330a CO — completeness, clarity, discrimination. You see findings before the PDF goes out.