Korean Share-Sale Tax: Residence, ISA and Employee Shares

Start with tax residence, the share type, the sale venue and your shareholder status. The same sale amount can fall under different Korean tax rules; a familiar company name or a foreign passport alone does not decide the treatment.

Define the taxable event

Employment-related stock compensation and a later sale of those shares are separate events. For a sale, use the NTS guidance dated 3 February 2026 below and check the rules for the relevant income year.

• Qualifying small shareholders' sales of domestically listed shares on a Korean exchange are generally outside capital gains tax. This does not cover every off-exchange or unlisted sale, and does not remove dividend or transaction taxes.
• Large-shareholder status can depend on value or ownership-ratio tests. Check the applicable testing date, related-party rules and stock category rather than using only today's account value.
• A commonly applicable Korean-resident foreign-stock calculation is 22% including local tax after the applicable KRW 2.5 million annual basic deduction. Residence history, taxable scope and eligible annual netting must be checked; this is not universal for every foreign resident.

ISA contribution limits are not profit exemptions

The KRW 20 million annual and KRW 100 million total limits concern contributions. Qualifying net-profit exemptions are KRW 2 million for general accounts or KRW 4 million for eligible special categories; excess taxable profit is separately taxed at 9.9% including local tax. Residence, account eligibility, permitted products and the three-year requirement matter.

Small shareholders' qualifying exchange-traded domestic listed-share gains are generally already outside capital gains tax in an ordinary account. An ISA is not automatically an extra exemption for those gains. Compare the account's actual mix of taxable income, costs and restrictions.

Pension accounts and foreign-stock losses need their own checks

Pension withdrawal treatment depends on the source of funds, age, qualifying pension conditions and withdrawal method. Do not compare a single pension tax rate with an ordinary account without those conditions. Permitted investments also differ.

Where a Korean-resident foreign-stock sale is within the applicable taxable scope, eligible gains and losses in the same tax year may be netted. Confirm the scope, transaction costs, other gains and applicable deduction before considering a sale. A potential tax reduction is not a guaranteed investment gain, and it does not justify assuming a future repurchase price.

Prepare a pre-sale file

1. Identify residence history and the relevant tax year.
2. Separate compensation income from acquisition cost and later sale proceeds.
3. Record exchange or off-exchange venue, dates, fees and share type.
4. Check shareholder status and the applicable account rules.
5. Reconcile eligible annual gains and losses and ask a qualified adviser about any unresolved treatment.

Sources

• NTS share-sale tax guidance, 3 February 2026 (Korean)
• Samsung Securities ISA rules (Korean)
• English tax resources and model limitations

Scope: This is an explanation and planning checklist, not a recommendation to buy, sell or allocate a specified share of your assets. Examples exclude costs and taxes unless stated. Market outcomes and individual employment terms can differ.