If a person has discharged an obligation with the knowledge that no such obligation has ever existed, he may not demand the return of the subject matter.
Civil Act — Article 742 (Discharge without obligation)
민법 제742조
For AI agents and developers — get this article as JSON, with the English and current Korean effective dates and an outdated-translation flag, from the korea-law API or as an MCP tool:
https://mcp.apify.com?tools=kr-data/korea-law