Let's start with the first code

-to display your IMEI number dial
                         *#06#
You will find this number also on the box of your mobile.
the following codes will show you the version of your phone, when it was made and when it was bought

-           *#0000#
The next code is for your warranty

               *#92702689#
If you want to stop the sim clock. (this code is used to save battery life)

-              *#746025625#
when you know your master code which is based on your IMEI number press the following
          #pw+(master code)+1# for provider lock status
           #pw+(master code)+2# for network lock status
           #pw+(master code)+3# for provider lock status
           #pw+(master code)+4# for sim-card lock status

eg +pw+1234567890+1#
*3370# and EFR will be activated after a reboot of the phone ( consumes more power )
#3370# and EFR will be switched off after a reboot of the phone.

Half Rate will give you bad sound quality, which gives the service provider the opportunity to have more calls on the network; and you might get a lower charge from them. (Will give you 30% longer talk-time)

*4720# Half Rate coded will be activated after a reboot of the phone (better standby time)
#4720# Half Rate coded will be de-activated after a reboot of the phone
Type *#746025625# [*#sim0clock#] to check if the SIM Clock can be stopped.
Type in *#92702689# [*#war0anty#]
With a Nokia 16xx/21xx/31xx/51xx/81xx that are SIM locked to one provider you can bypass the SP lock like this:
Insert SIM card of different provider.

Turn on the phone and press the UP VOLUME key for 3 sec. then release it and the phone says PIN CODE ?

Press the "C" key.

Then Press * and wait until it disappear and appear again, then press * one more time and 04*PIN*PIN*PIN#

The phone now says: PIN CODE CHANGED (or ACCEPTED) and the SIM card is accepted until you restart the phone again.

Nokia have removed this trick from newer phones.
*#92702689#
This will show ya warrinty d-tails and how many days u'v ad it 4 ,scroll through tha menu 2 fing this .(2 get out of the menu press the "off button"). *#war0anty# - Warranty

*3370#
This code improve'z tha soundz quality ,but decreases the battery life.

#3370#
Deactivates tha code a-buve.

*#0000#
Shows ya fones software version.

*#06#
Shows ya IMEI number.

*#sim0clock#
This is gonna show ya if your fone will allow simclock stoppage.

*4370#
1/2 Rate Codec activation. It will automatically restart.

#4370#
1/2 Rate Codec deactivation. It will automatically restart.

*#92772689#
U kan check ya ISDN by enterin' tha a-buve code
  NOKIA CODES
BATTERY BOOST CODE: *3370#
SIM CLOCK STOP CODE: *#746025625#
HALF PRICE CALL CODES: #4720#
SERIAL NUMBER: *#06#
SOFTWARE VERSION: *#0000#
SECRET MENU: *#92702689#

CURRENT WORKING FREE TEXT CODE IS +44802000341 AND +85292040031 ALSO USE THIS ONE BUT BE WARNED THIS IS SLOW +905429800064 REMEMBER ALWAYS USE THE +44 FORMAT WHEN DOING THESE FREE TEXT! EG. 07944123456 WOULD BE +4407944123456! VISIT OFTEN FOR MORE UPDATES ON FREE TEXT CODES!
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