Indonesia's September inflation rises to 3.28%, leaving 0.22 pp below BI's ceiling

Facts

Headline: Statistics Indonesia (BPS) reported on 1 October that consumer prices rose 3.28% year on year in September (up from 3.19% in August). ¹ Month on month, prices rose 0.30% (up from 0.21% in August), and the year-to-date increase reached 2.17%. ²

Drivers: the food, beverages and tobacco group rose 4.37% and contributed 1.28 pp to annual inflation. ³ BPS named fresh fish, chicken, chillies, rice and cooking oil. Transport prices rose 4.84% on gasoline, airfares and vehicle maintenance, and personal care and other services rose 7.77%, driven by jewellery prices. ⁴ Raw chillies were the largest monthly contributor.

Regional spread: provincial inflation ranged from 2.55% in South Sumatra to 7.59% in North Sulawesi. ⁵

Policy context: Bank Indonesia held the BI-Rate at 5.75% on 23 September (unchanged; third consecutive hold). ⁶ In its September Asian Development Outlook, ADB raised its 2026 inflation forecast for Indonesia to 3.3% (raised from 3.0% in ADO July 2026) and kept its growth forecast at 5.2% (unchanged from ADO July 2026). ⁷

Analysis

Over two months the headroom to the 3.5% ceiling has narrowed from 0.31 pp in August to 0.22 pp in September. ⁸ With the rate on hold to support the rupiah, a breach of the band in the fourth quarter would reduce Bank Indonesia's room to ease and keep bank funding costs where they are.

Across the Maritime group Indonesia sits in the middle: August inflation was 1.9% in Malaysia and 6.1% in the Philippines. The composition matters more for lenders than the level. Food, the group with the largest contribution, weighs most on lower-income households, which are the core of micro, multifinance and online-lending books.

Household credit was already cooling before the September print: bank consumer credit growth slowed to 5.0% in August (down from 5.3% in July 2026). ⁹ The wide provincial range, from 2.55% to 7.59%, means national averages understate the squeeze on borrowers in high-inflation provinces.

Implications

Counterpoints and uncertainties

Volatile food prices such as chillies can reverse quickly after harvests, and part of the increase comes from gold jewellery, which reflects global gold prices more than household demand. Headline inflation remained inside the target band in September, so a breach is a risk, not a base case.