For reasons best known to the caller, some certain people may decide to hide their number before calling you, here’s how to unhide a private number.
Method 1(Without Internet)
Step 1. While your phone is ringing, don’t pick it up.
Step2. Wait for at least 15minutes
Step 3. Dial *#30# the hidden number will be revealed on the screen.
Note: In some cases it will take up to 24 hours before it will show the number.
Method 2
Step1. Download and install truecaller from google play store
Step2. Leave your internet connection on whenever a call from a hidden number comes in, true caller will search and reveal the callers name.
Note: It works faster with 3G, 3.5G, 3.75G or 4G(takes 2 to 5minutes to reveal the caller’s ID).