Trying to pull phone number and combine it with carrier, cannot find phone number variable
if you don't already have it, get DEVEL module. In your tpl file, use dpm($account); this will output the array. From there you can determine the proper element names.

it would be $field_phone_number[0]['value']; a trick to figuring out the exactly lineage is to progressively use dpm, ie: dpm($account), dpm($field_phone_number), dpm($field_phone_number[0]), etc. this is an easy one, but arrays can get in depth and complicated within Drupal 

Devel:


  Helper functions for Drupal developers and inquisitive admins. This
  module can print a summary of all database queries for each page
  request at the bottom of each page. The summary includes how many
  times each query was executed on a page (shouldn't run same query
  multiple times), and how long each query took (short is good - use
  cache for complex queries).
      Also a dprint_r($array) function is provided, which pretty prints arrays. Useful during development. Similarly, a ddebug_backtrace() is 
  offerred.