Based upon my research, the final HDB hotline is 1800-225-5432 . It is a Branch Business office Assistance Line that operates on weekdays from eight:00 AM to five:00 PM.Also, there are actually other Get in touch with numbers for particular solutions:* HDB Primary Line: 6490-1111 (for basic enquiries, weekdays 8:30 AM - five:00 PM)* click here