Determined by my research, the general HDB hotline is 1800-225-5432 . This is a Department Office Support Line that operates on weekdays from 8:00 AM to 5:00 PM.Also, you will find other Speak to figures for precise products and services:* HDB Main Line: 6490-1111 (for basic enquiries, weekdays 8:30 AM - 5:00 PM)* Essential Maintenance Services