What are the consequences of not filing capital gains tax?

If you do not file a preliminary or final return, the government determines the tax and notifies you, and a penalty tax for failure to file (20% or 40%) and a late payment penalty tax of 0.022% per day may be added.

If the tax payable exceeds KRW 10 million, you may pay part of it in installments within 2 months after the payment deadline. Check the National Tax Service's guidance for deadlines and calculation methods.