Finding the flat
Finding a flat in big cities is not always easy. In our case we had to start searching about 4 months before the relocation. The most common way to look for a flat is through websites. I was surprised at first, as in Italy it is still common to call real estate agencies and look for newspaper adverts. However, the majority of private individuals and most of the real estate agencies will advertise on websites. The most employed website for flat renting is immobilienscout24.de. Another notable website is immowelt.de.
I do not advice going to a real estate company for having them do the search for you. The reason is that there is a fee to pay, which is up to 3 months of your rent, that is owed by whoever requires the service. This fee is paid by the landlord when the house is already advertised and you find it by yourself.
My advice for contacting the landlord or the handling real estate agency is to prepare a short, concise letter about yourself and who is going to accompany you. It helps to mention that you have certain academic degrees or your job. Do not be afraid to establish a contact for tens of those flat entries. The demand is sometimes so high that you are not even going to receive a reply.
The renting contract
Eventually, you will receive some positive replies. You will agree to visit the house with the landlord or the handling real estate agency. If all goes well, a contract (Wohnraummietvertrag) will be signed by both parties. I am not spending many words on the contract itself. Read it well, and ask for help to your German friends and colleagues. If the contract is a standard one (likely obtained from hausbesitzerverlag.de), you have to check the added clauses (Sonstige Vereinbarungen) near the end of it. These clauses will specify extra rules, e.g., do not make holes in the bathroom tiles. Also be aware that the house’s rules (Hausordnung) are part of the contract. Breaking the house’s rules might have you kicked out of the house.
The landlord’s declaration of occupancy
Together with a copy of the renting contract, your landlord must provide you a declaration of occupancy (Bestätigung des Wohnungsgebers). It must be signed by your landlord. This is mandatory by law, as you will need it when you register your residency.
In Italy, you would be left on your devices regarding utilities (water, energy, gas, etc.). In Germany, it is your landlord who is responsible for providing initial contracts with the utility companies. Therefore, you will relocate to a flat which provides utilities. For this reason, you should attempt to open a bank account before relocating to your new flat. The reason is that the utility companies would like to setup a SEPA Direct Debit mandate for you to pay the bills. You are free to move to different utility companies once relocated.