Can I cancel a Seoul apartment lease early if the landlord won’t fix mold, and get my deposit back?

Based on what you described (serious mold and ongoing water leakage), early termination may be available if the defects materially interfere with normal residential use and the landlord has failed to repair despite your repeated requests. Under Korean law, landlords generally have a duty to maintain/repair the premises so that the tenant can use it as intended. However, to terminate on the basis of non-repair, it is usually necessary to show more than “there is a problem”—you should be able to prove:

1. 
   

   Materiality of the defect (severity and impact on habitability/normal use)

   
   


2. 
   

   Clear repair requests made to the landlord (ideally in writing)

   
   


3. 
   

   A reasonable cure period provided after the request (and, if possible, a final notice)

   
   


4. 
   

   Non-performance (no repair, inadequate repair, or unreasonable delay)

   
   

If these elements are met, termination can be asserted and you can demand return of the full security deposit (less any undisputed rent/utility arrears or agreed deductions). The practical issue is often not the legal basis, but proving the facts and managing the handover/return process cleanly.

We are happy to assist with your recovery of the deposit.