At the turn of the year 2025/2026 the National Council passed two packages of laws that have been in force since 1 January 2026: the 5th Rent-Related Inflation Relief Act with the new Mieten-Wertsicherungsgesetz and the Civil Law Indexation Adjustment Act. They mainly affect rent increases, fixed-term contracts and the recovery of money. Here you will find an overview of the changes – each with the date from which they take effect.
The laws at a glance
The 5th Rent-Related Inflation Relief Act (5. MILG) was promulgated on 30 December 2025. It contains the new Mieten-Wertsicherungsgesetz (MieWeG) and amends the Mietrechtsgesetz (MRG) as well as the Richtwertgesetz [S1]. The Civil Law Indexation Adjustment Act (ZIAG) was promulgated on 29 December 2025 and amends the ABGB and Konsumentenschutzgesetz [S2]. The rules on how high the rent may be at the time of contract conclusion remained essentially the same; what changed primarily were the adjustments of ongoing rents and the fixed-term provisions [S1].
- Indexation capped (MieWeG) – effective from: 1.1.2026, also for older contracts; Source: [S3][S4]
- Stricter cap 1% / 2% for rent ceiling adjustments – effective from: adjustments in 2026 and 2027; Source: [S3][S6]
- Minimum fixed term of 5 years for entrepreneurial landlords – effective from: contracts and renewals from 1.1.2026; Source: [S5][S7]
- Recovery from indexation in old contracts limited – effective from: from 1.1.2026; Source: [S4]
- Clarifications on indexation clauses (ABGB, KSchG) – effective from: 1.1.2026, also for older contracts; Source: [S2]
Rent increases: one date per year, a statutory cap
For main and sublet contracts for flats in the full and partial application scope of the MRG the contractually agreed indexation has been limited since 2026 by a statutory calculation model [S3]. Adjustments are made at most once a year on 1 April; the relevant figure is the inflation of the previous year, and the portion above 3% counts only half [S3]. For the first adjustment only the proportion of whole months after contract commencement counts [S3]. Cooperative flats are generally excluded [S3].
These limits apply not only to new contracts: they must also be applied to increases under contracts from before 2026 that take effect or would have taken effect from 1 January 2026 [S4].
Hypothetical example: A contract from 2022 provides for an index adjustment each July. The increase calculated for July 2026 can, since the reform, take effect at the earliest on 1 April 2027.
It is also new that an indexation for room rents can be agreed by a mere reference to the statutory model [S8].
Old building and regulated rents: 1% and 2%
Where the rent ceilings of the MRG apply, inflation in 2025 may be incorporated into the adjustment by at most 1% and inflation in 2026 by at most 2% [S3]. The statutory reference values were also allowed to rise by at most 1% on 1 April 2026; on 1 April 2027 it is at most 2%, and from 2028 the portion above 3% is halved [S6]. The MRG provides the same steps for the category amounts [S9]. Already in 2025 the then-planned increase of reference values and category amounts on 1 April 2025 had been cancelled [S10].
Fixed term: five instead of three years for entrepreneurial landlords
Fixed-term residential leases in the full and partial application scope must since 2026 be concluded for at least five years where the landlord side is an entrepreneur within the meaning of the Konsumentenschutzgesetz; otherwise the minimum remains three years [S5]. The same applies to any extension and to automatic renewal where no one reacts after expiry [S5]. Whether a landlord is to be regarded as an entrepreneur depends, according to case-law, on the scope and organisation of the letting; the burden of proof lies with the landlord to show otherwise [S15].
The new rule concerns contracts concluded after 31 December 2025 or contractually or legally renewed; previously agreed fixed-term arrangements remain subject to the old legal situation [S7].
Hypothetical example: A property company offers an extension of three years in February 2026. This fixed term would not be enforceable; the contract would be considered indefinite [S5].
Recovery of payments from ineffective index clauses
If an indexation clause in a residential tenancy agreement concluded before 2026 is ineffective, you can only reclaim payments from the last five years – calculated before the end of the contract or, for an ongoing contract, before your knowledge of the ineffectiveness [S4]. From that knowledge the claim becomes time-barred after three years [S4]. Not covered are claims that were already pursued in court before 2026, clauses that are abusive within the meaning of the EU Directive on unfair terms (EU-Klauselrichtlinie), and exceedances of statutory rent caps [S4].
Further changes from 1 January 2026
- Two-month rule: The prohibition of price increases within two months of conclusion of the contract does not apply to long-term obligations intended for prolonged performance – and therefore, as a rule, not to tenancy agreements. This also applies to older contracts [S2][S11].
- Older index values: The ABGB now sets out criteria by which clauses with a base value established before conclusion of the contract are to be assessed [S12].
- Procedural costs: If you are represented in a tenancy law proceeding by a representative within the meaning of the MRG, for example by a tenants’ association, any reimbursement of costs increases to 800 euro in the first instance and 360 euro in the second and third instances; this applies to proceedings initiated from 2026 onwards [S13][S7].
- Usufruct: If from 2026 you rent a condominium from a person who holds a usufructuary right (Fruchtgenussrecht) over that apartment, this is considered a primary tenancy (Hauptmiete) [S14][S7].
What you can do now
When faced with an increase, check whether the timing and percentage fit the statutory model, and for fixed-term contracts look at the date of conclusion or renewal. In case of doubt, the Arbeiterkammer of your federal state, tenants’ organisations and – in Vienna – the Schlichtungsstelle can help.