Indonesia's Big Banks Under Margin Pressure in Q3 2026 as BI Holds Rate at 5.75%
Mandiri's NIM slid to 4.43% as funding costs rose, while earnings at BNI and Mandiri stayed solid and the index fell 3.49% on October 29.
Major Indonesian banks remain under net interest margin pressure in the third quarter of 2026, The Jakarta Post reported on October 29. Bank Mandiri's consolidated NIM slid from 4.89% to 4.56% and then 4.43% on a quarterly year-on-year basis, with its cost of funds up 30 basis points.
Bank Indonesia held its benchmark rate at 5.75% to defend the rupiah, which traded above Rp18,130 per US dollar, and will ease reserve requirements in stages from November 1, 2026, lowering the conventional GWM from 9% to 7%. On October 29 the Jakarta index fell 3.49%, with the financial sector the largest negative contributor and foreign net selling reaching Rp1.52 trillion, according to Kontan.
Earnings remain solid despite the margin squeeze: BNI booked a Rp16.1 trillion profit, up 6.6% year on year, while Bank Mandiri posted Rp45.5 trillion, up 20.7%. The combination of thinner margins and rising funding costs is pushing banks toward operational efficiency programs.