The indexation clause of the rent of a

Application pratique:

The Court of Cassation ruled that a fixed base index is allowed as long as the index variation period corresponds with the rent variation period. Marc must check if the lease's annual rent change period exactly matches the 12-month index change period he intends to use (e.g., from 4th quarter to 4th quarter). If not, he should adjust the calculation to avoid the clause being struck down, potentially saving litigation costs.

Application pratique:

Under this case law, the indexation clause is valid only if the period of index variation correlates with the rent variation period (e.g., if index published in March reflects change from previous year Q4 to Q4, and rent review is on anniversary date in April, that might be fine). Sophie should request the landlord's calculation details, compare the index base dates, and if they don't correlate, formally contest the increase in writing, referring to Article L. 112-1 and this decision. She may need to seek legal advice to avoid paying an unlawful increase.

Application pratique:

The Cassation decision clarifies that as long as there is a correlation between index variation and rent variation periods, the clause stands. Amélie should instruct her notary or solicitor to review each lease's exact wording: for each, identify the index publication schedule and the lease's review timing. If any clause uses a mismatched period (e.g., index change over 15 months), she should negotiate a lease amendment with the seller before purchase to avoid future disputes with tenants and potential invalidation of the clause.