How to identify a call made to a mobile number is local or STD OR ISD

Question

I am developing some kind of Android application, but I don’t know how to get data for numbers that the called number is local or STD.

ieFrom Where do apps like Mobile Number Checker get data? https://play.google.com/store/apps/details?id=com.cliqs.mobilelocator&hl=en

Note. I'm talking about a mobile phone number, not about fixed / fixed numbers.

Answer 1

The number you get has a type string. Thus, you can get the first few digits of the number and request it with a database containing std codes (if any). Good luck

Answer 2

See link for ISD definition.

Below is the answer to Local and STD calls in India.

Suppose you know to which state (Telecom Circles) an outgoing call is being sent. Then you just need to check if your local state (Telecommunication circles) corresponds to the "outgoing call" ("Telecommunication circles") state or not. If this is the same, then calls the local else STD call.

Now the problem boils down to how to find the status (Telecom Circles) of outgoing calls.

This can be easily done for Landline phones, where we specifically set STD codes. See Link for status and there are STD codes.
Interestingly, mobile phones also follow something very similar. The first 4 digits of the mobile number indicate this. For example, suppose the number is 9999xxxxxx, then this number from Delhi is Vodafone. See the wikipedia link for full mobile phones from the first four-digit details.