New rent = current rent × new index ÷ base index. Any cap or collar in the lease then applies.
Compare my rent with the marketFrequently asked questions
Which index applies to an office lease?
Office leases in France are most often indexed to the ILAT (office and service-sector rents index), and retail leases to the ILC (commercial rents index). The ICC (construction cost index) can no longer be used for new commercial leases since 2014, but still appears in older leases.
How is commercial rent indexation calculated?
Multiply the current rent by the new index and divide by the base index, taking the same quarter one year apart for annual indexation.
Can a sharp increase be challenged?
If indexation moves the rent by more than 25% compared with the last rent set, either the tenant or the landlord can ask for it to be reviewed to the market rental value (Article L145-39 of the French Commercial Code).