The taxation will also apply to bitcoin mining operations and income from initial coin offerings, should it be approved by Parliament.
South Korea's Ministry of Economy and Finance proposed the amendments to the existing tax law to include the cryptocurrency industry, with backing from the Ministry of Information and Technology.
In September, the Ministry will table the amendments before Parliament. Once approved, the law will enter into force in 2021, allowing authorities to tax profits generated from the sale of digital assets for cash. Trades between cryptocurrencies will remain tax-free, and similarly those sold at a loss.