Delinquency rates among low-credit self-employed borrowers have risen sharply at KB Kookmin, Shinhan, Hana, Woori and NH NongHyup, widening the gap with stronger borrowers. The average delinquency rate for Grade 10 borrowers, the lowest tier in the Financial Supervisory Service's 10-grade system, reached 44.64% at the end of August 2026, up from 38.20% at the end of 2025; one bank reported 71.03%. Grade 9 delinquency rose from 4.56% at the end of 2021 to 23.58%, while Grade 7 increased from 1.68% to 6.58%. By contrast, Grade 3 delinquency fell to 0.05%, and Grade 5 remained below 1%. The figures are simple averages across the five banks, and the highest-grade categories can fluctuate because of small loan balances and borrower counts. Rising market rates, including a one-year bank bond yield above 4%, could add to repayment pressure. Bank of Korea minutes also highlighted worsening delinquencies and deepening polarization, while banks warned that deteriorating asset quality could lead to tighter credit screening.