Here’s a full write-up on how to unblock a private (or restricted) number, depending on your device and phone carrier. A private number (also called unknown , restricted , blocked , or no caller ID ) means the caller has deliberately hidden their number using Caller ID blocking (often by dialing *67 before your number in the US). If you previously blocked such calls—or want to ensure you receive them again—here’s how to reverse it. 1. Unblocking via Your Phone’s Built-in Settings (Android & iOS) Most modern smartphones have a “Block unknown/private callers” feature. If you turned that on, private numbers go straight to voicemail. To undo: