Twilio does not work!! Please Help!

I'm trying to work with Twilio in a Mobile application, I've already made the Twilio Connector configuration, but I do not know how to make it work. I have the number that Twilio provides, but when I try to call a cell phone number, it throws an error. There is something else that I have to configure and I did the step by step. By the way, I'm trying to call a Colombian cell phone number and I already have a Colombian number on Twilio.

I do not need a International permission because the number that I have is from Colombia.

not sure but try to get rid of the international number +571  or +57.

This is a very late response but I think most new users (especially people in the US) experience this problem when they first sign up for Twilio.  I did recently, so I thought I'd share how to fix it.

Twilio requires that you whitelist specific countries in the Voice Geographic Permissions settings (there is also a counterpart for SMS).

It is a fairly straightforward process:

1.  Login to
2.  Click the ellipsis button (...)  to expand the navigation menu on the left-hand side
3.  Select Programmable Voice in the Cloud Communications section
4.  Click Calls in the submenu
5.  Click Geo Permissions
 *   If the layout changes, you can also just type in "Geographic Permissions" in the quick search in the top right-hard corner of the screen
6.  Select the countries that you want to set as "low risk" (i.e. enable calling/sending SMS messages for)
7.  Click the Save button