Apps How to anonymize phone number

[Zigmaphi]

I'm designing an android app. It pairs phone numbers to user IDs and allows you to dial a phone number via the ID by pulling the phone number from a web-server and dialing it with the native android phone application. However I want the native android phone app to show the ID instead of the phone number. Is this possible and how do i achieve it.

This is important because in my environment, the phone number of a contact varies often and the best way to handle this is changing the phone number attached to an ID.

 

[gerbyte]

Unless you use an app on the destination phone and the call is done via VOIP (or oter way) then I don't think it is possible to "disguise" a phonecall by the network provider.
I could be wrong in saying that, but as phonecalls are managed by the phone network provider then I imagine they wouldn't allow this. It would probably act as a massive security risk if phonecalls could be disguised.
You might me able to log all incoming calls though and filter the phone number via the webserver, and if it exists allow the app to kick in and display respective userID?

 

[Zigmaphi]

@gerbyte,

Masking the phone number is only so the caller can't see the phone number he's calling. As it stands now, the callers tend to continue dialing a number even if the receiver has changed location and the receiver has to respond to the customer even if he doesn't have his history.
If the caller has the receiver's ID, he can continue calling the same receiver's ID.

The phone number is shown everywhere beyond the phone.