20% over 3 years: the most rent can rise
If the lease says nothing about increases, the landlord may propose higher rent only up to the usual local level and by no more than 20% over three years.

If the lease neither regulates nor excludes rent increases, the landlord may propose in writing an increase up to the comparable usual rent in the area. Together with any increases in the past three years, the rise may not exceed 20% (Act No. 89/2012 Coll., Section 2249(1)). The proposal can be made only after 12 months without an increase.
Example: you pay CZK 15,000 and the rent has not risen in the past three years. The landlord may propose at most CZK 18,000, and only if that amount is usual in the area. Different rules apply if your lease provides for annual increases, for example in line with inflation (Civil Code, Section 2248).
What it means for you
- You agree? You pay the higher rent from the third month after receiving the proposal (Civil Code, Section 2249(3)).
- You disagree? If you do not agree in writing within 2 months, the landlord may go to court within a further 3 months (Civil Code, Section 2249(3)).
- A proposal without the new amount or without evidence of the usual rent is disregarded (Civil Code, Section 2249(1)).
Source: e-Sbírka: Act No. 89/2012 Coll.

