You can also have a backup phone number on most websites (google, github, dropbox).
If you lose your phone you call your carrier to block that sim card and request a new one anyway, so you're not locked out.
If you lose your phone you call your carrier to block that sim card and request a new one anyway, so you're not locked out.
About my previous reply, that is if I recall correctly, I remember being able to cancel numbers of lost phones providing the number and the name of the owner (in this case, one time I lost my number, other times my dad lost his')