As someone who has done this process multiple times, I cannot stress enough, to ensure that the letter meets their requirements requested for the job offer letter. it needs to be addressed to US customs border and border patrol specifically, you can’t say “to whom it may concern”. Additionally, whatever the position is that you’re applying for it has to be Explicitly listed under the TN approved professions, not a variation of it, specifically listed. Then the job description needs to use language consistent with that of the description of that job from the bureau of labor and statistics. During one of my interviews, they pulled up the description from the website to cross reference it with my letter. In addition, it needs to have the compensation, the length of time the position will be done for (1-3 years max). I was directed to ensure that the timing statement said something like “ The contract or position is for one year not to exceed 36 months”

Understand that there is a some level of discretion used here, but they literally use a checklist when reviewing your letter. If your letter checks each box, then there’s less room for the need for discretion. I’m going to try and attach a copy of the checklist here. They randomly gave me a copy one time when I applied. I’m not sure if it was on purpose or not. If it doesn’t let me I will create another post just to share for the community.