17 Secret iPhone Interrogation Codes
iphone imei interrogation1. IMEI Number | Code: *#06#
The International Mobile Equipment Identity number is a 15-digit code that uniquely identifies your iPhone within GSM, UTMS and all other mobile phone networks. It’s always printed on your iPhone’s original delivery box and is required in the unfortunate case that your iOS device is lost or stolen. IMEI is required when filling a complaint to the police and when addressing the insurance company. This identification number can be also found in Settings -> General -> About.

iphone field test menu2. Field Test | Code: *3001#12345#* + ‘Call’
By accessing the hidden iPhone field test mode you’re able to find out live updated information about your cell phone network. You can uncover the numerical value of your cell phone signal and read data about surrounding cell towers. If you tap on the numerical valued carrier signal, available in the top left corner of your screen, you can switch between graphic and numerical display. Numerical values are always negative. Figures around ‘-50’ are for optimal reception while those towards ‘-120’ are considered very poor.

3. Call Barring | Status: *#33# | Turn ON: *33*pin# | Turn OFF: #33*pin#
These secret codes help you to check the restriction status of all your outgoing calls, data usage, texts and so on. Call barring is used to protect yourself from accidental calls when you allow your child to play with your iPhone, for example. iOS currently doesn’t offer a menu Setting for blocking outgoing calls. You could partially solve the problem by turning on Airplane Mode. However, this can be turned back off easily by anyone. Instead use the above codes to block or unblock all outgoing calls. Replace ‘pin’ with your SIM card pin, NOT iPhone Passcode!

call waiting status interrogation4. Call Waiting | Status: *#43# | Enable: *43# | Disable: #43#
This short code interrogates your device if Call Waiting is enabled or not. This setting allows you to be able to receive other calls while you’re already engaged in a conversation. The second and other callers will be cued in the waiting line. You’re notified with a sound alert when another call is waiting for you and have the option to decide if you wish to maintain the actual conversation, decline the new one or keep one of them on hold until you finish the other. Within iOS, call waiting is available in Settings -> Phone -> Call Waiting.

iphone call forwarding status5. Call Forwarding | Status – All: *#21# – Unreachable: *#62# – When Busy: *#67# | Disable All Forwarding: ##002# + ‘Call’
Whenever you’re busy or on holiday you can redirect your calls to another colleague or family member. Use the nearby mentioned secret code and interrogate your iPhone about its current call forwarding settings. Besides voice data, you can also check out forwarding for data and faxes. Redirecting voice calls can be also set up from the iOS Settings -> Phone -> Call Forwarding. Use the other codes to check call forwarding status, when phone is out of reach or when busy.

outgoing call anonymity6. Outgoing Call Anonymity | Status: *#31# + | Current Call: #31#phone-number + ‘Call’
When initiating and outgoing call you have the option to make your phone number available for the receiving caller or to hide it. Anonymity status can be checked with the first of the first code provided above. To initiate an anonymous call you can either edit your contact or directly use your iPhone keypad to add the #31# code in front of the dialed phone number. Else, if you wish to hide your number in all outgoing calls, visit the iOS Settings -> Phone -> Show My Caller ID menu.

call line presentation status7.Incoming Call Presentation | Status: *#30# + ‘Call’: shows if your iPhone will display the number of incoming calls.

8. SMS Message Center Number | Check: *#5005*7672# + ‘Call’: get your carrier’s text message center number.

9. EFR Mode | Code: *3370# + ‘Call’: Enhanced Full Rate is a speech codding standard that improves voice quality for GSM conversations. It also burns a little more battery life. (not available on all networks.)