For your very first contract with the DMOE, you will get 300,000 KRW deducted from your first two months' paycheck, totaling 600,000 KRW.
Please make sure that you sign the consent form allowing your school to hold this money from your paychecks. If you do not sign the form then you will have to go through the hassle of transferring the money to your school's bank account, 300,000 KRW for the first two months, totaling 600,000 KRW.
Understand that this safety deposit doesn't just cover any potential liabilities for your apartment, but also any school property or any other fees that your school may have to incur due to your direct actions. Your security deposit of 600,000 KRW should be refunded to you during the last month of your first contract as long as there are no damages done to the school provided housing, school property, no costs to pay, etc. If the damage or costs incurred exceeds the amount of the security deposit, then it will be deducted from your final paycheck, as stipulated in your contract (Article 12, Clause 1 and 8).Your security deposit may also be used to cover any other liability, claims, suits, losses, costs and/or legal fees that your school may incur due to any direct actions by the NET (Article 20). In other words, it is not strictly related to your apartment.
Please remind your co-teacher or financial administrator when the time comes that you should receive your security deposit back. As long as there are no costs that needs to be deducted from your security deposit as mentioned above, then you should receive the full amount back.
No security deposit will be deducted at the start of any subsequent contracts.