I am about to open a phone decoding business and need to no software specified for that and how to go about it. What I mean is phones used by different networks in different countries do not take the service providers network in my country, so need to be decoded to take them.

Lococo10,

You are doing this backwards. You should learn how to do the decode first before opening the business.

A word of caution for you. Decoding phone code (programming) may put you at odds with the code owners, especially if the coding is copyright protected.