COFIX-Based Variable Mortgage Rates Halt Uptrend...Down 0.12%p for the First Time in 5 Months

2.77%, Down 0.12 Percentage Points From December 2025

The Cost of Funds Index (COFIX), which serves as the benchmark for variable-rate mortgage loans in the banking sector, has declined for the first time in five months.

According to the Korea Federation of Banks on the 19th, the COFIX based on newly handled funds for January 2026 was compiled at an annual rate of 2.77%, down 0.12 percentage points from December 2025 (2.89%).

COFIX is the weighted average interest rate on funds raised by eight domestic banks, and it reflects changes in the interest rates of deposit and savings products, as well as bank bonds and other funding instruments actually handled by banks. A drop in COFIX means that banks can secure funds while paying less interest.

In contrast, the balance-based COFIX rose by 0.01 percentage points from 2.84% to 2.85%. The "new balance-based COFIX," introduced in June 2019, also increased by 0.01 percentage points, from 2.47% to 2.48%. The new balance-based COFIX additionally includes interest rates on other deposits, borrowings, and settlement funds.

Commercial banks plan to apply the COFIX rates released on the 19th to new variable-rate mortgage loans as early as the 20th.