Preparing for Korea’s 2027 Crypto Tax Regime: What Every Investor Needs to Know

Background

South Korea passed an amendment in December 2024 to the Income Tax Act, establishing that starting January 1, 2027, gains arising from the transfer or lending of virtual assets will be taxed as ‘other income,’ separate from regular income stream. (g.nts.go.kr) Prior to that, the measure’s implementation was delayed to allow taxpayers and the tax system time to prepare. (g.nts.go.kr)

Key Features of the Crypto Tax Regime

• What is taxed: The income from transfers (e.g. selling or swapping cryptos) or lending virtual assets. (g.nts.go.kr)
• Basis for cost deduction:
  • If the acquisition cost is clear: actual cost plus related expenses.
  • If not: an eligible flat-rate cost allowance up to 50% of the proceeds. (g.nts.go.kr)
• Cost methods:
  • For trades via registered virtual asset service providers: moving-average method.
  • Others (e.g. OTC trades): first-in-first-out (FIFO). (g.nts.go.kr)
• Special rule for assets held before enactment: For virtual assets held before Jan 1, 2027, the deemed acquisition cost (if actual cost is unknown) is the greater of the market price as of December 31, 2026 or the actual acquisition cost. (g.nts.go.kr)
• Rates and thresholds:
  • Taxed as separated miscellaneous income at 20% rate. (g.nts.go.kr)
  • Basic exemption: KRW 2.5 million per taxpayer annually. (g.nts.go.kr)

Practical Planning Steps

1. Document all transactions now: Keep wallet records, transaction history, receipts—these will matter for cost basis.
2. Identify service provider type: Whether you use a registered exchange (moving-average) or not (FIFO) will affect your tax impact.
3. Evaluate whether to recognize unrealized gains now: If you hold assets pre-2027, assessing their fair market value as of end-2026 helps if exact acquisition cost is unclear.
4. Plan trades or lending wisely: Holding assets across the cut-off date may change your deductions; lending or leasing cryptos platforms need scrutiny.
5. Estimate your tax and project liquidity: With a 20% tax on net gains and documentation requirements, ensure you can pay any liabilities—especially since tax returns are due in the following year.

Case Example

Mr. Kim bought 10 ETH on June 1, 2025 for KRW 6 million. He also has bonus ETH from an airdrop, acquisition cost unknown. On March 15, 2027, he sells 5 ETH for KRW 8 million.

• For the 5 ETH from his purchase: cost basis via moving-average method = about KRW 3M, gain ~ KRW 5M taxed 20%.
• For the airdropped ETH: since acquisition cost is “unknown,” the deemed cost = market price as of December 31, 2026 if greater than any actual cost, else actual cost—but then expenses capped.

Actionable Advice

• Consult with a tax advisor to set record systems.
• Use tools or wallets that export cost basis and transaction ledger in detail.
• If you expect large crypto gains, consider spreading transactions to avoid pushing into higher effective tax liabilities (due to loss deductions, if any).
• Check any double taxation treaties if you hold or transact via overseas service providers.

Bottom line: From Jan 1, 2027, profits from crypto transfers and lending will be taxed at 20% after your cost basis (actual or deemed) and eligible expenses. Good documentation today can save surprises later. Knowledge + records = smoother compliance.