I am a UK user of this plugin, which means I've been updating the carriers' table specifically for UK users.
However, when I used the shortcode on a sidebar to encourage visitors to subscribe via SMS. I gave it a go by putting in my phone number but it is only accepting 10 digits long phone numbers. So I tried dropping the 0 at the start and it didn't works.
So, really, I need it to accept UK mobile numbers which are 11 digits long.