Short Answer
Short-term sublets are highly susceptible to tax evasion and illegal arrangements that prevent you from completing your mandatory address registration.
Landlords frequently rent out temporary rooms without the primary owner's permission, leaving the subtenant with no legal rights.
What Most Expats Don't Realize
You booked a cheap three-month room from a local student who was traveling abroad for an internship. You asked for the official landlord confirmation to register your address at the city office, but the student refused because their main rental contract banned subletting. Because you accepted an illegal sublet, you could not register your residence, resulting in a €300 government fine and a forced transition into a premium business hotel.
What To Do
- Open the search filters on WG-Gesucht and limit your targets specifically to listings marked as "Zwischenmiete".
- Ask the main tenant for written proof of the owner's written permission to sublet before you move in.
- "Ist die Anmeldung hier offiziell möglich?" (Is address registration officially possible here?) — demand an answer to this question before transferring any money.
The Truth
Germany's residential registration laws make zero exceptions for short-term occupants. The system penalizes unauthorized sublets automatically, treating undocumented temporary residents as non-compliant entities regardless of their lease duration.