Background
In December 2021 our client lent KRW 250,000,000 to Mr. A, repayable in three months, deducting KRW 15,000,000 in advance interest and handing over KRW 235,000,000. Mr. B jointly guaranteed the debt the same day. After the due date, Mr. A repaid only KRW 50,000,000, and our client sued both men for the remaining KRW 185,000,000 plus late-payment damages.
What Was at Stake
Mr. B argued that our client had extended the due date without his consent, releasing the guarantee, and that our client had ignored his request to secure Mr. A's assets, so his liability should be reduced under the principle of good faith.
How Changchun Helped
Law Firm Changchun represented the lender, and both courts accepted its position. A creditor's delay in taking legal action does not by itself show an intent to extend the due date, and Mr. A's statement that he had agreed to repay the rest later was not credible given the size of the debt. A creditor also owes a guarantor no duty to preserve the principal debtor's assets, and a guarantor who signed at the debtor's request could have protected himself by claiming reimbursement in advance once the original due date passed.
Outcome
In September 2024 the first-instance court ordered Mr. A and Mr. B to pay KRW 185,000,000 plus late-payment damages, jointly and severally. Mr. A did not appeal. In February 2026 the appellate court dismissed Mr. B's appeal and ordered him to bear the appeal costs.
A joint guarantor cannot escape liability merely because the creditor was slow to press for payment; an extension of the due date must be clearly proven. (Outcomes depend on the facts of each case.)