Now first you need to find out whether your mobile is locked or not.
1. When your smartphone accepts only one sim. For example if your mobile is locked with us cellular sim. Then you cannot use any other sim like at&t or t mobile sim with your android smartphone.
2. When you insert new sim you get message that sim restricted or sim card not accepted. It means your mobile is locked.
3. When you insert a sim you get message like contact your service provider or invalid microchip or enter sim unlock code. It means your mobile is locked.
4 there are many such messages which indicate that your mobile is locked.
Sim locking defines the only network which your gsm mobile can use. When sim locking done your smartphone can only use the network which your sim locked with. Your smartphone can not use other network. For example if your android is locked with at&t then you cannot use t mobile sim, us cellular, orange sim without unlocking your smartphone. More importantly tracfone use t- mobile and us cellular network as a host network but if your android locked with tracfone you can not allowed to use even t mobile or us cellular network. As while your phone locked with tracfone it can only use sub network of trackfone only.
Sim locking means you cannot access any other network other than that locked sim. If you want to use other network than you need to get unlock codes for your smartphone mobile. For that you need to generate unlock code for your mobile from imei no.
Gsm, cdma and 4g lte are the three kind of mobile networks which are used now a days. Let me brief you,in gsm mobile network information are stored within sim card. For example if you are using t mobile, at&t or us cellular sim then accordingly gsm network information about your sim is stored within your sim card and locked with sim card.
While in cdma mobile network information is programmed with codes and these codes are integrated with your cdma mobile software. You cannot use gsm sim on cdma network and cdma mobile on gsm network. But with 4g lte technology you can use gsm and cdma both on same mobile. And one exception in Canada is that bell and tenus has done some excellent work and now you can shift from cdma to gsm. But this is not applicable to all cdma and gsm network.
Now to sim unlock your mobile, you need to get smartphone sim unlock codes from imei no of your mobile phone. For that you need following details regarding to your mobile phone.
1. Imei number of your smartphone.
2. Mcc – mobile country code and mnc- mobile network code.
Below is the list of mcc and mnc code for various gsm sim providers and cdma service provider
Verizon US: mcc code 310- 310 is same for all cdma and gsm network for United States
Verizon US : mnc code for verizon cdma -005 and mnc code for lte Verizon : 012
At&t US :mcc code-310.
At&t US : mnc code gsm 850 – 030.
At&t US : mnc code gsm 1900 - 080
T mobile US: mcc code -310.
T mobile US : mnc code gsm 1900 -160.
T mobile US LTE 1900/1700 – 260.
US cellular gsm mnc code-066 and cdma mnc code – 220.
For Canada- mobile country code – 302.
Bell cdma 800/1900 – mobile network code – 640.
Telus cdma 800/1900 – mobile network code -650.
Roger wireless gsm 850/1900 and lte 1700 – mnc -720.
3. Gsm sim card serial number /ssn :
Normally sim card serial no is 19 digits. It is written on cover of your sim card and many gsm sim providers have written serial no on back side of sim card.
4. Make and model of your android smartphone.
Now a days it is not possible to get master unlock code for any mobile brand. You need to provide exact information about your android phone model like lg g2 or lg g3 or Samsung galaxy a5 or galaxy j7 or galaxy s5 s6 etc. even you need to provide your android os details like jellybean or sandwich or kitkat. For each version sim unlock codes are different.
5. In some mobiles like blackberry sometime it require uptime or total usage of mobile till date. For that in newer smartphone go to setting- about phone. Here you will get the information of mobile uptime.
Above information are enough to generate sim unlock codes for any mobile. Many online unlock code generator also require all above information. From only imei number you cannot generate sim unlock codes for android smartphone. You need all the above information.