Open Decision Ledger · Civil obligations & remedies
Collusive breach of the mortgage ban on rental housing
Supreme Court, Nov. 13, 2025, 2025Da210805 (judgment)
No holding summary · checked against points at issue. The official text publishes no summary of the holding for this decision. The quotation and factors in this record are copied verbatim from the points at issue; the evidence for each axis is taken from the points at issue, the order and the reasons.
Case name: 근저당권말소
Official text on the National Law Information Center
Question
Is Article 18(1) of the former Rental Housing Act only a police provision, so that an act breaching it is not automatically void, and is an act done by parties in collusion to breach it void as contrary to good morals and public order?
Holding
Article 18(1) of the former Rental Housing Act is a police provision only, so an act in breach of it is not automatically void. Where the parties acted in collusion to breach it, however, the act must be held void as an act contrary to good morals and public order. The Supreme Court held that the circumstances in the record raised a strong likelihood that the first-instance co-defendant and the defendant lenders colluded, and that the court below had misread the law and failed to examine what it needed to.
Points at issue, verbatim
당사자가 통정하여 위와 같은 단속규정을 위반하는 법률행위를 한 경우, 선량한 풍속 기타 사회질서에 반하는 법률행위로서 무효인지 여부(적극)
Unofficial English translation
Where the parties, acting in collusion, entered into a juristic act violating such regulatory provision, whether it is void as a juristic act contrary to good morals and other social order (affirmative)
Disposition
Reversed and remanded Stated in the decision
원심판결을 파기하고, 사건을 광주고등법원에 환송한다.
Unofficial English translation
The judgment of the court below is reversed, and the case is remanded to the Gwangju High Court.
Form of the test
Elements stated Stated in the decision
그러나 당사자가 통정하여 위와 같은 단속규정을 위반하는 법률행위를 한 경우에는 선량한 풍속 기타 사회질서에 반하는 법률행위로서 무효라고 보아야 한다.
Unofficial English translation
However, where the parties, acting in collusion, entered into a juristic act violating such regulatory provision, it must be regarded as void as a juristic act contrary to good morals and other social order.
Factors
- 구 임대주택법 제18조의 규정 취지
- 구 임대주택법 제18조 제1항의 법적 성질(=단속규정) 및 이를 위반한 법률행위가 당연 무효인지 여부(소극)
- 당사자가 통정하여 위와 같은 단속규정을 위반하는 법률행위를 한 경우, 선량한 풍속 기타 사회질서에 반하는 법률행위로서 무효인지 여부(적극)
Unofficial English translation
• The purport of the provision of the former Rental Housing Act, Article 18
• The legal nature of Article 18 (1) of the former Rental Housing Act (= regulatory provision) and whether a juristic act violating the same is automatically void (negative)
• Where the parties, acting in collusion, entered into a juristic act violating such regulatory provision, whether it is void as a juristic act contrary to good morals and other social order (affirmative)
Relation to precedent
Follows earlier decisions Stated in the decision
대법원 2006. 12. 7. 선고 2006다49796 판결
Unofficial English translation
Supreme Court Decision 2006Da49796 decided December 7, 2006
Decisions referred to
대법원 2006. 12. 7. 선고 2006다49796 판결, 대법원 2024. 7. 25. 선고 2022다204333 판결(공2024하, 1463)
Burden of proof
Not addressed Not in the decision
Open question and revisit condition
How much knowledge and agreement between the lessor and the lender must be established before a mortgage registered in the gap between the ownership transfer registration and the new accessory registration is held to be a collusive act void as contrary to good morals and public order?
The remand judgment of the Gwangju High Court on whether the first-instance co-defendant and the lenders colluded will show how this rule is applied to these facts. Any later decision on Article 18 of the former Rental Housing Act or on the corresponding provisions of the Act on Special Cases concerning Private Rental Housing, and any change to the registration precedents cited in the reasons, would require this entry to be read again.
Cross-family AI independent reading & axis check
7 of 8 axes matched GPT-6 Astra (OpenAI, codex CLI) · 2026-10-24
A reader from another model family (GPT-6 Astra), given the official text but not the primary reading, agreed on 7 of the 8 axes; the readings differed on axis 8 (open question and revisit condition).
Axis 8 (Open question and revisit condition): Primary “How much knowledge and agreement between the lessor and the lender must be established before a mortgage registered in the gap between the ownership transfer registration and the new accessory registration is held to be a collusive act void as contrary to good morals and public order?” vs Independent “Will further examination on remand establish collusion sufficient to invalidate the mortgages at issue?”
The primary asks what degree of knowledge and agreement constitutes collusion during the registration gap, whereas the independent asks whether collusion will be established on remand.
당사자가 통정하여 위와 같은 단속규정을 위반하는 법률행위를 한 경우, 선량한 풍속 기타 사회질서에 반하는 법률행위로서 무효인지 여부(적극)Raw responses and comparison record: Protocol · Blind readings (JSONL) · Axis comparison (JSONL) · SHA-256 (JSON)
Lower-court contrast & scope of application
Lower-court reading vs. Supreme Court holding
Lower-court context: The Gwangju High Court, in its judgment of 13 February 2025 (2023Na20906), held that the cancellation of the earlier accessory registration was lawful and that the defendants' intent to evade Article 18 of the former Rental Housing Act could not be established, so that the mortgages in suit were not acts contrary to public order, and it rejected the plaintiffs' claim for cancellation of the mortgage registrations.
Supreme Court standard: The Supreme Court held that Article 18(1) is a police provision, so that breach of it does not make an act void of its own force, but an act done by parties in collusion to breach it is void as contrary to good morals and public order. It held that the circumstances set out in the reasons, including the increase in the risk to the tenants' priority conversion right, the lenders' awareness of it, their acquiescence in the delayed accessory registration and their active cooperation in the joint application for the mortgage registration, showed a strong likelihood of collusion. It reversed the whole judgment for misreading the law on the validity of an act breaching Article 18(1) and failing to hold the necessary hearings, and remanded the case to the Gwangju High Court.
Distinguishing conditions
- Since the voidness turns on the parties' concerted act, an act breaching Article 18(1) done by one party alone, without collusion between the lessor and the lender.
- A security interest in the nature of a restricted right for the Housing and Urban Development Fund, like the earlier mortgage in this case, which Article 18(1) did not prohibit.
- Since the Court relied on both, a case in which the lender did not acquiesce in the delayed accessory registration or cooperate in registering the mortgage during the gap.
Record verification notes
First sort the security interests into those for the Housing and Urban Development Fund and those for an ordinary financial institution, since only the latter were prohibited. Then match each fact relied on for collusion, the loan application papers and appraisal documents, the internal approval documents, the awareness that conversion was scheduled after 29 December 2019, and the joint registration application, against the file, because the Supreme Court left the finding of collusion to the court below on remand. The decision says nothing about who must prove the collusion, so gather what shows both the lessor's and the lenders' knowledge and agreement, and confirm which version applies, since Article 18 was deleted by the Act on Special Cases concerning Private Rental Housing wholly amended by Act No. 13499 of 28 August 2015.
From the official text
Points at issue
구 임대주택법 제18조의 규정 취지 / 구 임대주택법 제18조 제1항의 법적 성질(=단속규정) 및 이를 위반한 법률행위가 당연 무효인지 여부(소극) / 당사자가 통정하여 위와 같은 단속규정을 위반하는 법률행위를 한 경우, 선량한 풍속 기타 사회질서에 반하는 법률행위로서 무효인지 여부(적극)
Unofficial English translation
The purport of the provision of the former Rental Housing Act, Article 18 / The legal nature of Article 18 (1) of the former Rental Housing Act (= regulatory provision) and whether a juristic act violating the same is automatically void (negative) / Where the parties, acting in collusion, entered into a juristic act violating such regulatory provision, whether it is void as a juristic act contrary to good morals and other social order (affirmative)
Summary of the holding
The official text publishes no summary of the holding for this decision. The quotation and factors in this record are copied verbatim from the points at issue; the evidence for each axis is taken from the points at issue, the order and the reasons.
Order
원심판결을 파기하고, 사건을 광주고등법원에 환송한다.
Unofficial English translation
The judgment of the court below is reversed, and the case is remanded to the Gwangju High Court.
Provisions referred to
구 임대주택법(2015. 8. 28. 법률 제13499호 민간임대주택에 관한 특별법으로 전부 개정되기 전의 것) 제18조(현행 삭제), 민법 제103조, 제105조
Read 2026-10-24 · Cross-read 2026-10-24. All quotes matched against the official text. The Chinese-character placeholders the court used for anonymised parties are given in their Korean readings, and parenthetical Chinese-character glosses are omitted.
Every entry is published only after all quotes have been matched character by character against the official text, and audited by an independent second reading from a different model family across all eight axes. Both agreed axes and text-grounded interpretive divergences are recorded openly. The ledger is a research record, not an assessment of the court or advice on any matter.
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