FlatronL1917

I am looking for an informed opinion on our Indexmiete clause. Yes, I am a member of the local Mieterverein and yes, I will talk to an attorney in the near future. But I have learned a lot through TT and I believe it is worth asking here too.   We entered our apartment in April 2021 with a typical renting contract. In October 2022, the landlord transferred the ownership of the building to his children through founding a separate GbR and sent us a new contract with Indexmiete to fight the rising inflation. What rubbed me the wrong way was a phrase he added in a letter accompanying the contract: "Wir möchten, dass sich für Sie als Mieter nichts ändert und schicken Ihnen daher einen Mietvertrag zu, damit das Mietverhältnis mit Ihnen weiterläuft.". I found this sentence indirectly threatening and very manipulative, but I was not a member of the Mieterverein back then, did not research enough and decided to sign the contract after a lot of stressing about it. Even though it should not be this way, I admit it got a bit personal for me.   A summary of the relevant clause in the contract: (1) The rent increase is applied from the 01. January every year (2) Last year's consumer index is published around February, but we are supposed to pay retroactively the difference for the weeks from 01. January up to February and the new rent for the rest of the year   Yesterday (February 2023, about 5 months after signing the new contract) we received notification that the rent was supposed to rise according to the new consumer index. I am now very annoyed about it and researched the hell out of this topic. I was wondering if someone could confirm / deny the following points / theories: (A) The rent cannot be increased at the moment, because it has not been 12 months since we signed the new contract [1] (B) Even if he could raise the rent, he could only do that 2 months after communicating this decision, so starting in the beginning of May [2] (C) Point (B) also implies that the process described in the contract is invalid. He cannot increase the rent every 12 months, because there has to be 12+2 months (for the communication, according to (B)) between each rent increase; all agreements that diverge from the law and are against the tenant are invalid [1] (D) The final question is if (C) invalidates the Indexmiete clause completely or if this means that we will continue our tenancy with a normal Indexmiete clause, in the proper way described by the law   Sources: [1] BGB 557b [2] BGB 558b   The lawyer of the Mieterverein did not seem to want to spend a lot of time on my case when I told him we had already signed a contract with an Indexmiete. I also had not thought of all these fine details back then and you only get a 20 minutes talk with him, so it is kind of understandable. A new appointment for a short talk is being scheduled. My plan is to talk to other tenants as soon as possible and coordinate against the increase.   Thank you for reading my post. I will gladly answer any questions.