Crypto tax in South Korea: the tax starts in 2027, and your basis is set on 1 January
After three deferrals the charge is now written into the statute for 1 January 2027. The part almost nobody explains correctly is the transition rule: for anything you already hold, your acquisition cost becomes the greater of what you actually paid and the market price at the cut-over. That sounds generous, and for a winning position it is. For a losing one it is a trap that only records can spring you from.
Which exchanges report on you, and since when? — the free lookup →
| Tax rate | 20% national plus 2% local — 22% combined — on the year's net gain after a KRW 2,500,000 deduction. Note the shape: the same deduction is applied independently in each statute against the same base, so it is not a 10% surtax on the national figure.1 |
| The KRW 2.5m is also a floor | 소득세법 제84조제3호: where the year's 가상자산소득 is 2,500,000 won or less, no income tax arises at all.1 |
| How it is classified | 기타소득 — other income — and specifically 분리과세기타소득 under 소득세법 제14조제3항제8호다목. It never joins your global income and never meets the 6–45% ladder. It is also not capital gains, so there is no holding-period relief and, as the statute stands, no loss carry-forward. Losses within one year do net.2 |
| The transition rule | 소득세법 제37조제5항, in terms: for virtual assets already held before 1 January 2027, the acquisition cost is the greater of the market price as at 31 December 2026 and the actual acquisition cost. The snapshot is a floor on your basis, not a replacement for it.2 |
| When the snapshot is taken | Not the close of 31 December. 소득세법 시행령 제88조제2항 measures the price posted at 00:00 on 1 January 2027, averaged across the operators the NTS designates. A daily close or a December average is the wrong number.3 Unverified: the NTS notice designating operators for INCOME-tax purposes has not been published; the existing notice names five exchanges for inheritance and gift valuation, which is a different data item measured differently |
| Cost-flow method | 총평균법 — total average, computed per resident per asset (시행령 제88조제1항, as amended 28 February 2025). This replaced the earlier per-wallet moving-average and FIFO rules; guidance still describing 이동평균법 predates the amendment.3 |
| Declaring | Self-assessed. Filed as separately-taxed other income during the ordinary window, 1–31 May of the following year — so the first return is May 2028 for the 2027 year. There is no withholding for residents.4 |
| Who knows | Korean exchanges already file 가상자산거래명세서 to the NTS under 소득세법 제164조의4. Korea signed the CARF agreement on 26 November 2024, collection began 1 January 2026, and the first international exchange happens during 2027.5 |
Tax authority: 국세청 National Tax Service (NTS); policy at 기획재정부, the Ministry of Economy and Finance — https://www.nts.go.kr
Why your records — not the rules — are the real problem
Here is the asymmetry worth understanding before you spend a weekend on this. If a position is above water at the cut-over, the snapshot is the greater figure and it carries you whether or not you kept anything. If it is underwater — you paid more than it is worth on 1 January — the greater figure is what you paid, and you only get it if you can prove it. So the value of reconstructing your history is computable, asset by asset, and for a portfolio bought cheaply it is genuinely zero. We would rather tell you that than sell you something you do not need.
Two corrections to what circulates in Korean commentary. First, the 50% deemed-cost rule is 제37조제6항 and reaches only assets acquired on or after 1 January 2027, at exactly 50% and forfeiting fees — it is not available to anything you already hold. Second, an asset with no quoted price at the cut-over, whether delisted, DEX-only or self-custodied, has no 시가 under either limb of the decree, and the statute provides no fallback. For those, documented cost is not the better answer. It is the only one.
That is the gap ClearBasis closes: we rebuild the complete acquisition history from exchange files and on-chain records, match every transfer between your own wallets so moving coins is never taxed as selling, and attach evidence to every number.
The assessment period is five years, seven where offshore transactions are involved, seven if no return was filed, and ten to fifteen in fraud cases (국세기본법 제26조의2). The practical horizon for a 2027 return touching any foreign exchange is therefore seven years from 31 May 2028.
What you can use today, in South Korea
The free scan shows your true gains against proceeds-only in about three minutes. The Global Basis Report (from $99) is the full evidence-linked ledger — acquisition costs, disposal gains, local-currency values with cited FX — the document you or your accountant declare from.
Run my free scanComing for South Korea
Declaration formatting for South Korea — your report's totals mapped to the local return's fields, reviewed by a local tax professional before we ship it, and this page published in ko · en. Run and save a free scan to join the list: you will be emailed the day it opens, and demand decides how fast.
Start with the free scanQuestions people in South Korea actually ask
Is the 2027 start date actually final this time?
It is what the statute says, fixed by the amendment of 31 December 2024, and the government's 2026 tax reform package published on 3 August 2026 did not defer it again. A bill to abolish the tax outright was referred to subcommittee in July 2026, so a fourth deferral remains legislatively possible until the end of the year. We are telling you what the law says today, not predicting the National Assembly.
If I have no records, am I taxed on the whole sale price?
No — and this is the most common misconception. For a pre-2027 holding the greater-of formula resolves to the 1 January snapshot, which becomes your basis. You are never pushed to a zero cost. What you lose is only the amount by which your real cost exceeded that snapshot.
Does the 50% rule help me?
Only for coins you buy from 2027 onward, and only where you acquired them outside an exchange and genuinely cannot substantiate the cost. It is fixed at exactly 50% of the total disposal value for the whole of that asset, and it forfeits your fees. It does nothing for what you already hold.
What about a token that is delisted or only on a DEX?
That is the real gap. The decree sources the snapshot from prices posted at an operator, and for an asset nothing quotes there is no figure under either limb. The 50% fallback does not reach pre-2027 holdings. Documented acquisition cost is the only route to a basis at all, which makes those the assets to reconstruct first.
What if I am not a Korean resident?
A different regime entirely. For a non-resident, withdrawing virtual assets from a Korean operator is itself treated as a disposal, and the operator withholds the lesser of 10% of the gross payment or 20% of the gain — 10% of gross where cost is unproven. There is no KRW 2.5m deduction.
The primary sources listed below are monitored for change. Confirmed factual updates publish with a new version stamp; substantive rule changes are verified by a professional before this page changes. Where a claim carries an unverified badge above, it means the authority's own site refused us access to the document that would settle it — we would rather show you the gap than paper over it.
1. 소득세법 제64조의3, 제84조 — rate, deduction and de-minimis floor · 2. 소득세법 제21조제1항제27호, 제14조제3항제8호다목, 제37조제5항·제6항 — classification and the transition rule · 3. 소득세법 시행령 제88조 — snapshot price source, reference instant, total-average method · 4. 국세청 — 거주자의 가상자산소득 과세 개요 · 5. OECD — CARF multilateral agreement signatories (Korea, 26 November 2024). Retrieved 28 August 2026. This guide is information, not tax advice; rules change — the page is versioned (kr-2026.1), re-reviewed annually, and the English master is canonical. For binding answers, consult the authority named above or a licensed local tax advisor. Every country we cover → · How South Korea compares with thirteen others →