Inflation clause (indexation)
An inflation clause in a lease sets out how the rent may change in line with inflation. It must be clear which index you will use, for what period and how the change will be made. Rising prices alone do not give you the right to raise the rent automatically.
Also known as: rent indexation, rent valorisation
What the clause should clearly state
The Civil Code allows the parties to agree on an annual rent increase. A well-drafted clause specifies which index the amount follows, for which period, from what date and whether you must give notice of the change. It is also worth covering rounding and what happens if inflation is zero or negative. The basis for such an agreement is § 2248.
Be careful with a bare phrase like “according to ČSÚ inflation”. The Czech Statistical Office publishes several indicators. The average annual inflation rate compares the average price level over two full years. Year-on-year inflation for a specific month compares that month with the same month of the previous year. The resulting percentages may differ.
How the increase is calculated
According to ČSÚ, the average annual inflation rate for 2025 was 2.5%. To illustrate: your lease refers to exactly this indicator and its conditions for a change are met. Rent of 20,000 Kč would then rise by 500 Kč to 20,500 Kč. This is not an instruction to raise all rents from January: the effective date follows from the lease. ČSÚ explains the indicators and their values.
Rent indexation does not by itself set new advance payments for water, heating or other services. Those are handled separately. Nor does inflation tell you what a comparable flat in the building next door is currently renting for. Price trends across the whole economy and conditions in the local rental market are two different things.
At Flat Service, we review rent on one-year leases according to market conditions and agree any change through an amendment. It is not an automatic inflation-linked increase. If you use your own inflation clause, check its exact wording and the correct Czech Statistical Office (ČSÚ) figure. Your notice should state the current rent, the percentage applied, the new amount and the date from which the change takes effect.
Sources checked on 13/09/2026. A general explanation does not replace a review of your specific contract or individual legal or tax advice.
← Back to the glossaryWould you like a rental without worries?
We take care of tenants, contracts, payment monitoring and repairs. In a free consultation we go through your flat and recommend how to set the management up.