Based on my look for, the final HDB hotline is 1800-225-5432 . It is a Branch Workplace Support Line that operates on weekdays from 8:00 AM to 5:00 PM.Furthermore, you'll find other Speak to figures for distinct companies:* HDB Major Line: 6490-1111 (for normal enquiries, weekdays 8:30 AM - 5:00 PM)* Essential Routine maintenance Company Device