The system must support three methods for adding a number to the blocklist:

Blocking and unblocking phone numbers are not merely technical features but social acts embedded in everyday communication. While blocking provides essential protection, unblocking offers a pathway to forgiveness or renewed contact. Understanding the motivations and outcomes of both actions can inform better design and healthier communication norms.

Unblocking simply removes the number from a local or network-side blocklist. In modern smartphones, this is a reversible database operation. VoIP services (e.g., WhatsApp, Telegram) maintain blocklists server-side, making unblocking instantaneous across devices.