Blocking And Unblocking Phone Numbers Portable Jun 2026

| Scenario | Expected Behavior | | :--- | :--- | | | The system should prevent users from blocking emergency services (911, 999, etc.). The "Block" button should be grayed out or disabled. | | Unknown/Private Numbers | Standard blocking blocks specific digits. If the user wants to block "Unknown" or "No Caller ID," this requires a separate toggle feature ("Block Unknown Callers"). | | Number Porting | If a blocked contact changes their number, the old number remains blocked. The new number is not automatically blocked. | | International Formatting | The blocking algorithm must normalize numbers. E.g., +1-555-1234 must be treated as the same entity as 555-1234 . |