diff --git a/phoneinterface.py b/phoneinterface.py
index 2b19688..9582b2a 100644
--- a/phoneinterface.py
+++ b/phoneinterface.py
@@ -159,6 +159,7 @@ class PhoneInterface(object):
             # Try to resolve prefix
             for p in self.__config.proxies:
                 if number.startswith(p.prefix):
+                    number = number[len(p.prefix):]
                     number += '@' + p.realm
                     break
         self.__core.invite(number)