If my financial income exceeds KRW 20 million, is all of it taxed at higher rates?

No. Under the special provisions of the Income Tax Act for calculating tax under comprehensive taxation, the withholding rate (14%) applies to financial income up to KRW 20 million, and only the portion above KRW 20 million is combined with other global income and taxed at the basic rates.

However, the tax calculated this way is compared with, among other things, the tax calculated by applying the withholding rate to all financial income, and the larger amount becomes the calculated tax. The actual burden depends on the size of your other income, so we recommend checking the National Tax Service's guidance or consulting a tax professional.