If you want to select a plan unique in that particular province, for example, Quebec, the number needs to be an area code within that province. Address may also be a concern. 

Thanks Goran. I was just going to update my own question. i went thru the process as tho I were going to add the line, and it did let me select the province and city where my son lives to assign a local number for him, which is great, so I completed the order  :)

That was the part I wasn’t sure about, and I didn’t want him stuck with a phone number for a different province if I had to get right to the end before finding out and it was too late. But I took the chance.

I’ll have to mail the sim card to him, as it was a bring your own phone plan, but that’s not a big deal.

If he is able to purchase a SIM card, it might be easier for him to do just that and activate that in self serve. Might save you the hassle of sending it and he can use his line that much sooner.