4 Code for iPhone

Signal Check
Input the following in the dial pad
*3001#12345#*
Then press "dial"
>-50dBm  indicates signal strength is very good

-50 to -70 indicates signal strength is pretty good

-70 to -90 indicates signal strength is normal

'-90' - '-100dBm' indicates signal strength is normal


Incoming Call status (turn on call forward or not)
Input the following in the dial pad
*#21#
Then press "dial"

IMEI Number

Input the following in the dial pad
*#06#
Then press "dial"


Show the Support Number of Service Provider

Input the following in the dial pad
*#5005*7672#

Then press "dial"