The Thai Chamber of Commerce University estimates the September-October 2026 floods will cost about 22,500 million baht in the base case, rising to 29,500 million if they drag on. Services bear the most (about 15,000 million), through lower spending, travel, restaurants and transport. Industry takes about 6,400 million, mostly from logistics and temporary plant stoppages; only one of 68 industrial estates was hit, in part. Bangkok and its vicinity are hardest hit. For a small business in affected provinces, expect weaker customer traffic and delivery disruption while water remains; the GDP outlook of 2.2-2.5% is unchanged.