Hej Mmitsop,
Your described situation happens to be a common occurrence, not unique to Sweden or for that matter, any other country.
No real need to pursue legal support in this.
With the interpretation of your contract (I'm assuming you are obliged to 1 month's notice and your landlord is obliged to 3 months notice), comes an important action step required from you too as tenant.
It's straightforward:
1. Your current landlord has indicated the needs for access to his/her apartment on Thursday 30 September.
2. You are free to find alternative housing in the meantime, BUT YOU ALSO NEED TO GIVE ONE MONTH'S NOTICE, despite being "under notice by your landlord". Yours to be served on the 1st day of a new calendar month.
3. Hypothetically speaking: should you find another place to rent as from 1 August, you will be obliged to pay for 2 places during August, since you may only give notice on 01.08.2021. However, you may vacate your current place any time during August since you've paid in advance. The handing over of current apartment in this scenario will then be on 31.08.2021.
4.Ìý You will then have NO further rental obligation to your current landlord for the month of September.
5.Ìý Both your current landlord and yourself have rights - you have not become a victim of circumstance overnight, despite a possible nasty surprise by receiving a 3-months notice period. From the sound of it, you did not expect to be finding yourself in search of new housing this time of the year. Best to keep emotions aside whilst your intellect hops into rationale thinking. Who knows? You may in future still pursue having a lasting friendship with your current landlord.
A few tips:
1.Ìý It's in your best interest keeping an amicable relation with your current landlord. I'm assuming the vibes were good since you've been living there for a number of years;
2.Ìý No reason to sabotage this relation. Your current landlord acted within his/her contractual rights according to the (presumed) existing/standard contract.
3.Ìý Your current landlord is going to become a REFERENCE for you, whilst seeking for a new place to live. From your side, give your current landlord no reason to compromise your name. That's what you have, only ONE NAME and it's not up for compromise. Keep your name unblemished.
4.Ìý What is SELDOM CLEAR, but mostly implied in standard rental contracts, is the fact that you as tenant remain contractually bound to also give one month's notice. Do so in line with my description above.
5. Put in all effort to leave your current apartment as clean and hygienic as possible and make sure that you've reported any possible damages/breakages to your current landlord way in advance. You will be needing your DEPOSIT in tact when you vacate your current apartment.
6.Ìý Ideally, try finding a new place from 01.10.2021 - then there will be no overlapping payments. But remember to then still give notice, ALWAYS IN WRITING, on 01.09.2021 for vacating on 30.09.2021.
This chapter should work out for you in a surprising way - different from what your initial response dictated to you.
All the best.