Require to be sent a text verification but I am not receiving any of those texts

Last night I changed phone lines, I was able to keep my phone number the same. Is it my iPhone or phone line that I should contact because as I am resetting my new phone I am logging into all my accounts and some require to be sent a text verification but I am not receiving any of those texts, can anyone tell me why?

[Re-Titled by Moderator]