fionasan wrote:Hi, I'm from Canada, planning to move to the States but don't have a job yet (I'm hoping to get a job once I get there). Is it possible to apply for a
TN visa once I'm already living in the US?
You can't just "move to the USA" unless you have another legal basis for coming here. If you don't have a job, the ordinary procedure would be that once you are invited for an in-person interview in the USA, you would cross the border to attend that interview. However, it is legal for other interviewing opportunities with other companies to find you in the USA once you have entered for your 1st interview. But just entering to job hunt, without the focus of a particular interview and especially if you say you are moving here, is apt to get you denied entry.
Of course you can always come here as a tourist, and, again, a job opportunity may legally find you while you are here as a tourist, but if you are out of work, it may be difficult to enter as a tourist. You need to entering for a clearly defined period of time to come here as a tourist and if your real intent is to stay until you find a job, they may ask probing questions at the border that will eventually ferret out the truth.
Once you have a job offer, I believe it would be legal to apply by mail to change status to TN, but AFAIK nobody ever does that for their first TN. The fastest way by mail, premium processing, still takes 15+ working days and costs $1000+. It is both cheaper and far faster to return to the border to get your first TN. People do routinely renew TN's by mail when time is not so much of the essence.
Unfortunately there's nowhere to go within the USA to get a
TN the same day. It can only be done--by law--in conjunction with an entry to the USA.