Yes, adult children can receive up to KRW 50M from parents tax-free within any 10-year period. Minor children have a lower cap of KRW 20M per 10 years. Prior gifts within the same 10-year window are cumulated.
Within 3 months from the last day of the month in which the gift was received. Voluntary filing within this period earns a 3% self-reporting tax credit.
Gifts made within 10 years before death are added back to the estate for inheritance tax calculation. Strategic lifetime gifting can reduce the overall tax burden, but must be carefully planned.