The rents in Berlin are still much lower than in lots of other world capitals, but the days when you could rent a centrally located flat for nearly nothing are definetely over.
Finding a permanent apartment if you are still abroad is difficult.  A new law – the “Bestellerprinzip” – came into force on June 1, 2015.  Now it is the owner has to  pay the estate agent.  This is good news for the tenants, but it makes it impossible to ask an estate agent to search the Berlin market for a permanent flat, even if you offer to pay for this service. Neither estate agents, nor platforms are  allowed to take money from tenants any more.
It is much easier to start looking for a permanent and unfurnished apartment when you have already arrived in Berlin.

Renting a temporary furnished Apartment

It is much easier to start by renting  a furnished apartment as it is more convenient and easier to secure. Nowadays, they all come fully furnished with internet, wifi, bedding, towels. cutlery,  plates, pots and all that you need.  Most of the furnished rentals have a minimum rental period of 2 or 3 months. Since you never know how long it takes to find a permanent flat,  you can easily commit to a few months.  In order to be on the safe side, you should arrange an option to extend in your rental agreement.
This means that you tell the owner one month before your rental agreement has terminated whether you want to extend the lease or not.  This makes you fairly flexible and you have the security of not being forced to move out. If you have an option to extend, the owner cannot rent out the flat to another tenant.

How to find an apartmnt in Berlin

Documents you need to secure an furnished Apartment

This is what you need: Work Contract, Proof of Education

Renting a furnished tempory apartment is much easier than renting a permanent flat.  First of all, there are apartments on the market and with most such flats there is less competition.
Owners are now not allowed to rent out their properties as holiday lets any more. This is another new law.  Owners can only rent out temporary flats to tenants who come to Berlin for work or for educational purposes (university, language course etc.).  When you apply for an apartment, you will be asked why you come to Berlin (to avoid renting out to tourists) and you might have to present a proof of a work contract.
Even if you don’t have a work contract yet, you still have good chances of finding a temporary apartment. If you work in the I.T. sector, for example, the chances of finding a job in Berln are very good. The owner or the agency will definitely know that you will be able to hand in a work contract later on.
If you attend university or do a language course, you should tell the owner where and what you study, and if and how you can pay the rent. You might have a scholarship or your parents might be paying.
The proof of work or study are the formal requirements, but the personal impression is just as important.  With furnished apartments, not only are you renting an apartment, but also the flat’s complete furnishings. Owners want to be sure that they can rent out to responsible tenants who look after the property, who do not party excessively, disturbing neighbours, or waste energy. Most owners who own well-kept apartments would rather leave their flat empty than renting out to the wrong tenant.
Renting a furnished apartment is very simple. You can either use the services of an agency or answer adverts of owners. Since the tenant does not have to pay any fees any more, renting through an agency is not necessarily more expensive. It is more convenient and agencies help you finding a flat that acutually suits your needs.  But it is worth checking price and quality.
When renting furnished apartments, you need a work contract or proof of untertaking further education.  Sometimes proof of income or some form of confirmation that you have enough funds to pay the rent does suffice. Normally owners do not ask for a SCHUFA.

 

Renting a permanent Apartment

SCHUFA

Once you live in Germany, you will get a SCHUFA – proof that you pay your bills and that you are not in debt. A SCHUFA is required when applying for a permanent, unfurnished apartment in Berlin and in the rest of Germany.

 

Mietschuldenfreiheitsbescheinigung

This is a certificate of rent paid that you get from your former landlord. You can also get it if you rent a temporary furnished apartment.

 

Proof of monthly income

You need to present payslips from the last 3 months or, if you are self employed, a BWA (Betriebswirtschaftliche Auswertung: economic evaluation) – also from the last 3 months.