Executive summary
Two Supreme Court decisions issued one day apart have resolved an important question concerning Korea's foreign tax credit limitation rules: when a Korean company has foreign operations in multiple countries and one country generates a loss, can that loss be confined to the country where it arose when calculating the foreign tax credit limit for the other countries?
The answer is no.
In both LG Chem (Supreme Court Case No. 2026두30340, June 25, 2026) and Hyundai Engineering & Construction (Supreme Court Case No. 2026두30552, June 24, 2026), the Supreme Court upheld the tax authorities' approach.
Where a Korean company has two or more foreign business operations and one jurisdiction generates a loss, the loss must be allocated proportionally based on the relevant country-by-country income amounts and reflected in the calculation of foreign-source income used to determine the foreign tax credit limit.
The practical consequence is important. A taxpayer cannot calculate the credit limit for profitable foreign jurisdictions as though a loss incurred in another foreign jurisdiction simply did not exist. The loss affects the overall foreign-source income calculation.
The LG Chem case also addressed a treaty argument involving the Korea-China tax treaty. The Supreme Court rejected the argument that the treaty independently prescribed a different calculation methodology, concluding that the treaty's credit provision did not displace the calculation required under Korean domestic tax law.
Who should read this
- Korean parent companies with foreign branches, offices, or other foreign business operations
- Tax teams calculating Korean foreign tax credits
- Groups with profitable operations in one foreign jurisdiction and losses in another
- Finance teams reviewing foreign tax credit calculations for prior open tax years
- Companies considering refund or amended-return claims involving foreign tax credits
- Tax directors assessing the impact of foreign losses on Korean tax liabilities
The short answer
If a Korean company operates in multiple foreign jurisdictions and one jurisdiction generates a loss, the loss cannot simply be isolated to that jurisdiction when calculating the foreign tax credit limitation. Instead, the loss must be reflected through an allocation methodology that reduces the foreign-source income attributable to the other relevant jurisdictions in proportion to their respective income amounts.
The Supreme Court's reasoning was essentially this: the foreign tax credit is intended to relieve double taxation of foreign-source income — not to allow a foreign loss to indirectly reduce Korean tax attributable to domestic-source income.
If the foreign loss were simply ignored when calculating the foreign-source-income numerator, the overall tax base would decrease while the foreign-source-income figure used in the credit-limit calculation would remain artificially high. That would effectively allow part of the foreign loss to reduce the Korean tax burden on domestic income. The Court considered that result inconsistent with the purpose of the foreign tax credit limitation system.
At a glance
| Issue | Taxpayer's position | Supreme Court's approach |
|---|---|---|
| Foreign loss | Keep the loss in the country where it arose | Reflect the loss through proportional allocation |
| Other foreign jurisdictions | Their income remains unaffected | Their foreign-source income is reduced proportionally |
| Foreign tax credit limit | Higher credit limit may result | Credit limit is reduced to reflect the foreign loss |
| Korean-source income | Loss can indirectly reduce the Korean tax burden | Foreign loss should not erode Korea's tax base on domestic income |
| Tax treaty | Treaty may prescribe a separate calculation | Treaty provision does not necessarily displace Korean domestic calculation rules |
Understanding the rulings
Why the foreign tax credit limit matters
Korea generally taxes a Korean resident corporation on its worldwide income. When the same income has already been taxed in another country, Korea's foreign tax credit system provides relief from double taxation. But the credit is subject to a limitation.
The basic policy is straightforward: a foreign tax credit should generally be limited to the amount of Korean tax attributable to the foreign-source income. This prevents foreign taxes from being used to reduce Korean tax attributable to income earned in Korea.
For the tax years at issue in these cases, the former Corporate Tax Act provided for a limitation based on the proportion that foreign-source income bears to the company's overall tax base. In simplified form:
Foreign Tax Credit Limit = Korean Corporate Tax × (Foreign-Source Income / Tax Base)
The difficult question arises when the company has both profitable and loss-making foreign operations.
Case background: the question the Supreme Court had to answer
Consider a Korean company with three foreign operations:
| Jurisdiction | Income / loss |
|---|---|
| Country A | KRW 50 billion profit |
| Country B | KRW 30 billion profit |
| Country C | KRW 10 billion loss |
The company has foreign tax payments in Countries A and B. The question is: should Country C's KRW 10 billion loss affect the foreign-source income used to calculate the credit limits for Countries A and B?
The taxpayer's preferred approach was essentially that Country C's loss stays in Country C, leaving the foreign-source income of Countries A and B at KRW 50 billion and KRW 30 billion respectively.
The tax authority's approach was different: Country C's loss must be allocated proportionally to the income-producing jurisdictions, reducing the foreign-source income used in calculating the relevant credit limitation. The Supreme Court upheld the latter approach.
What happened in the LG Chem case
In Case No. 2026두30340, the Korean company had foreign business operations in the United States, China, and other jurisdictions.
For its 2018 tax year, the company had originally calculated its foreign tax credit limitation using the allocation methodology later upheld by the Supreme Court. It subsequently filed a claim for correction, arguing that the loss generated by its U.S. operation should remain confined to the United States and should not reduce the foreign-source income attributable to other countries.
The tax authority rejected the claim. The Seoul High Court upheld the tax authority's position, and the Supreme Court dismissed the appeal on June 25, 2026.
The Supreme Court held that, under the former Corporate Tax Act, the foreign-source income used in the credit-limit calculation should be adjusted by allocating the loss in proportion to the relevant country-by-country income amounts.
What happened in the Hyundai E&C case
The Hyundai Engineering & Construction case involved a similar issue. The company had foreign operations in multiple jurisdictions, including the United States, the United Kingdom, Japan, Indonesia, and Saudi Arabia. The dispute concerned foreign tax credit calculations for the 2015–2017 tax years.
As in LG Chem, the taxpayer challenged the treatment of a loss arising in one foreign jurisdiction and argued that the loss should not reduce income attributable to other jurisdictions. The Supreme Court rejected the challenge on June 24, 2026.
The Court's reasoning was that if the foreign loss were not reflected against the income of the other jurisdictions, the loss would effectively reduce Korean-source income, thereby weakening Korea's domestic taxing rights.
Why the Court allocates the loss
This is the most important part of the rulings. The Court's reasoning can be understood through the structure of the foreign tax credit limitation itself. Suppose:
- Korean-source income = KRW 100 billion
- Country A foreign income = KRW 50 billion
- Country B foreign income = KRW 30 billion
- Country C foreign loss = KRW 20 billion
The foreign loss reduces the company's overall taxable base. If the loss is completely ignored in calculating the foreign-source-income numerator, however, the credit-limit calculation continues to treat Countries A and B as having KRW 80 billion of foreign-source income. The result is a mismatch: the denominator decreases, but the foreign-source numerator remains artificially high.
The Supreme Court considered it appropriate to adjust the foreign-source income figures correspondingly. In other words, the allocation methodology prevents the foreign loss from effectively being absorbed by Korean-source income.
The key principle: foreign tax credits are not a general loss-sharing mechanism
This distinction is easy to miss. The foreign tax credit system is designed to relieve double taxation of foreign-source income. It is not intended to provide a mechanism whereby foreign tax paid in profitable countries plus a loss in another foreign country equals a larger credit against Korean tax.
The Supreme Court's approach therefore preserves the connection between foreign income → Korean tax attributable to that income → foreign tax credit, rather than allowing the calculation to become disconnected from the actual foreign-source income after taking the foreign loss into account. That is the policy point behind both decisions.
The treaty issue in the LG Chem case
LG Chem raised an additional argument involving the Korea-China Tax Treaty, arguing that the treaty framework required a different treatment of the China-source income and prevented the U.S. loss from reducing the relevant foreign-source income.
The Supreme Court rejected that argument. The Court interpreted the relevant treaty provision as establishing the general principle that Korea should provide relief from double taxation through a foreign tax credit, while leaving the detailed calculation of the credit to Korean domestic law. Accordingly, the treaty did not itself prescribe a separate loss-allocation formula that displaced the Korean statutory calculation.
The practical implication: a treaty provision stating that foreign tax credit relief is available does not automatically mean that every element of the credit calculation is determined exclusively by the treaty. The domestic rules governing the computation of the limitation may still matter — particularly when a taxpayer is considering a treaty-based position that would produce a more favorable credit result than the Korean domestic calculation.
Practical example
Assume the following simplified facts:
| Jurisdiction | Foreign-source income |
|---|---|
| Korea | KRW 100 billion |
| Country A | KRW 60 billion |
| Country B | KRW 40 billion |
| Country C | KRW (20) billion loss |
The important point is not simply that Country C has a KRW 20 billion loss. The question is how that loss affects the foreign-source income attributable to Countries A and B for purposes of the Korean foreign tax credit limitation.
Under the Supreme Court's approach, the KRW 20 billion loss is allocated proportionally according to the relevant income amounts. Countries A and B therefore do not continue to carry their original KRW 60 billion and KRW 40 billion figures untouched.
For a group with substantial foreign tax paid in Countries A and B, the resulting foreign tax credit limitation may be materially lower than a calculation that simply ignores the Country C loss. The larger the loss — and the larger the foreign tax paid in the profitable jurisdictions — the more important the modeling becomes.
Practical insight: the important number is not just the foreign tax paid
Practical insight: a loss in a low-tax country can affect credits in a high-tax country
What this means for multinational tax teams
The rulings have a practical consequence beyond the two cases. A multinational group should not look at foreign tax credit calculations on a country-by-country basis only. Instead, the tax team should first understand the company's overall foreign-source income position. A calculation that appears reasonable when each country is reviewed separately may produce a different answer when the foreign operations are viewed together.
A useful review question is: "If one foreign jurisdiction generated a significant loss this year, have we reflected that loss consistently in the foreign tax credit limitation calculation for the other jurisdictions?" That question should be asked before finalizing the Korean corporate tax return — not only after a refund claim or tax audit begins.
What Korean companies often get wrong
Mistake #1 — Treating each foreign country as a completely separate calculation. Foreign tax credit calculations may be prepared country by country, but that does not mean a loss in one country can automatically be ignored when calculating the limitation associated with another country. Better approach: start with the company's overall foreign-source income and then apply the country-specific allocation required by the applicable rules.
Mistake #2 — Assuming a foreign loss should remain where it arose. This may appear intuitive from an accounting perspective. But the Supreme Court has confirmed that, for the relevant foreign tax credit limitation calculation, a loss in one foreign operation can affect the foreign-source income attributable to other jurisdictions. Better approach: model the impact of the foreign loss before determining the credit limitation.
Mistake #3 — Assuming a tax treaty automatically determines the calculation. A treaty may establish the obligation to provide foreign tax credit relief without prescribing every computational detail. The LG Chem decision is an important reminder that the domestic tax rules can still govern the mechanics of the limitation. Better approach: read the treaty and the Korean domestic provisions together rather than assuming one automatically overrides the other.
Mistake #4 — Recalculating a refund claim solely because a different method produces a larger credit. In both cases, the taxpayers' original calculations had used the allocation approach that was ultimately upheld by the courts. The later disputes arose because the taxpayers sought more favorable results through amended-return or correction claims. Better approach: before filing a refund claim, determine whether the proposed alternative methodology has a defensible legal basis — not merely whether it produces a larger refund.
Mistake #5 — Looking only at foreign tax paid. A large amount of foreign tax does not necessarily translate into a correspondingly large Korean foreign tax credit — the credit remains subject to the Korean limitation. Better approach: review three numbers together: foreign-source income, foreign tax paid, and Korean tax attributable to that foreign-source income.
Frequently asked questions
Does this ruling apply only to LG Chem and Hyundai E&C?
No. The decisions arose from specific taxpayers and tax years, but the Supreme Court's interpretation addresses the general calculation of foreign tax credit limits where a Korean company has multiple foreign operations and one jurisdiction generates a loss. The precise application still depends on the facts and the law applicable to the relevant tax year.
What if a Korean company operates in only one foreign country?
The specific allocation issue addressed in these cases arises because there are multiple foreign operations. If there is only one foreign jurisdiction, there is no second foreign jurisdiction across which the loss can be allocated. Other foreign tax credit limitation rules may still apply.
Does the ruling mean that every foreign loss is automatically allocated to every other country?
Not necessarily. The cases concerned the interpretation of the foreign tax credit limitation rules applicable to the taxpayers' circumstances. The relevant country-by-country income amounts, the nature of the foreign operation, the applicable tax year, and the governing statutory provisions must still be reviewed. The Supreme Court's point is that, where the allocation methodology applies, a loss cannot simply be isolated from the foreign-source income calculation.
Does a tax treaty override the allocation method?
Not automatically. In LG Chem, the Supreme Court rejected the argument that the Korea-China treaty independently required a different calculation methodology. The Court considered the treaty provision to establish the general foreign tax credit principle while leaving the detailed calculation to Korean domestic law. The wording of the relevant treaty should therefore be reviewed in each case.
Does this affect Korean companies with foreign subsidiaries?
The rulings specifically concerned Korean companies with foreign business operations/establishments and the calculation of their foreign-source income. A foreign subsidiary is a separate legal entity and its income is not simply the same as the Korean parent's branch income. Accordingly, companies should not assume that the rulings automatically apply in the same way to losses incurred by foreign subsidiaries. The legal structure and the applicable Korean tax rules need to be examined first.
Should prior-year foreign tax credit calculations be reviewed?
Potentially, yes. This is particularly worth considering where the company has multiple foreign business operations, one jurisdiction generated a material loss, the company paid significant foreign tax in other jurisdictions, and the relevant tax year remains open for correction, refund, or audit purposes. The review should compare the methodology actually used with the methodology confirmed by the Supreme Court and with the law applicable to that particular tax year.
Is this a new rule?
The better description is that the Supreme Court confirmed the interpretation of the applicable statutory framework rather than simply announcing a new administrative policy. The two decisions applied provisions of the former Corporate Tax Act to the relevant tax years. For current-year filings, the applicable current provisions should therefore be checked rather than assuming that every detail of the historical cases carries over unchanged.
Practical checklist
For Korean companies with multiple foreign operations, ask:
- Does the company have two or more foreign business operations generating foreign-source income?
- Did any foreign jurisdiction generate a significant loss during the relevant tax year?
- Was that loss reflected in the foreign-source income calculation used for the Korean foreign tax credit limitation?
- Were the other foreign jurisdictions' income amounts reduced using the appropriate allocation methodology?
- Was significant foreign tax paid in jurisdictions that otherwise generate substantial credit capacity?
- Does a tax treaty apply to any of the relevant foreign income?
- Does the treaty actually prescribe the calculation method, or does it leave the mechanics to Korean domestic law?
- Are there any open tax years for which a foreign tax credit calculation could be revisited?
- Do any pending refund or correction claims rely on isolating a foreign loss to the jurisdiction where it arose?
- Has the calculation been reviewed using the law applicable to the specific tax year?
Key takeaways
The Supreme Court's LG Chem and Hyundai E&C decisions are important because they establish a clear principle for a difficult foreign tax credit limitation question:
- A foreign loss cannot simply be isolated to the jurisdiction where it arose when the applicable foreign tax credit rules require proportional allocation.
- The loss can reduce the foreign-source income used to calculate credit limits for other foreign jurisdictions.
- The purpose is to prevent a foreign loss from indirectly reducing Korean tax attributable to Korean-source income.
- A tax treaty does not necessarily prescribe every computational detail of the foreign tax credit limitation.
- The rulings concerned former statutory provisions and historical tax years, so current-year calculations should still be tested against the current law.
For Korean groups with substantial cross-border operations, the practical lesson is simple: do not calculate foreign tax credits one country at a time and assume that the numbers are independent. A loss in one foreign operation can change the credit capacity generated by income and foreign taxes in another.
Related guides
- How Is a Foreign Corporation Taxed in Korea? The Corporate Tax Framework Explained
- Korean-Source Income for Foreign Corporations: Interest, Dividends, Real Estate, and Business Income
- Transfer Pricing for Korean Subsidiaries (coming soon)
- Withholding Tax in Korea: What Foreign Businesses Need to Know (coming soon)
- Korea's Foreign Tax Credit: A Practical Guide for Multinational Groups (coming soon)