Starting in June, Google are going to require telephone number verification for all numbers used in Call Extensions.
You can verify your numbers already, if you wish, but in June, if the numbers are still marked as "unverified" then the Call Extensions will be disapproved.
At the moment they are simply marked as "unverified" - an unsightly red mark on your campaigns and one which clients are (understandably) worried about. After all, anything that Google put in red on your account must be bad, right?
Well, yes and no. At the same time as they mark the number as unverified they also provide helpful guidelines to help you get verification. Helpful, possibly. But of the three options, a little like Goldilock's porridge, only one is "just right"... and even that one has some serious questions to answer.