Challenging initial rent: the 30-day deadline
When you move into a home in Switzerland, Art. 270 CO gives you a short window — generally 30 days from taking possession — to challenge initial net rent if it exceeds theoretical rent based on the previous tenant’s indexed rent under the legal rules.
What does Art. 270 CO cover?
This provision protects a new tenant against initial net rent clearly above what legal indexing of the previous tenant’s net rent would allow (reference rate and CPI under Art. 13 OBLF).
The challenge targets net rent at move-in, not a later drop in the reference rate — that falls under Art. 270a CO.
How the 30 days run
The deadline starts when you actually take possession (key handover), not when you sign the lease. The challenge must reach the landlord within this period — in practice by registered mail or acknowledged delivery, with reasons and, if possible, the theoretical rent calculation.
Keep proof of date and content. Swirent can help quantify the gap and draft a letter; sending and follow-up remain your responsibility.
If you miss the deadline
A late challenge may be inadmissible under Art. 270 CO. Other routes may still exist depending on facts (abusive rent, defect of consent, later Art. 270a CO reduction, etc.) — their admissibility is case-specific and often needs legal review.
Missing the deadline may forfeit the specific, fast lever of Art. 270 CO; acting as early as possible remains the best approach.
Useful documents for your file
Gather the lease, handover report, move-in date, initial net rent and, if known, the previous tenant’s net rent and fixation date. Without these, the legal calculation may be impossible or approximate.
Swirent analyses your scanned lease and estimates the gap; the result is indicative and does not replace personalised legal advice.