If you are a Canadian citizen, then you are not required to apply for a TN visa at a U.S. consulate.
You may establish eligibility for TN classification at the time you seek admission to the United States by presenting required documentation to a U.S. Customs and Border Protection (CBP) officer at certain CBP-designated U.S. ports of entry or at a designated pre-clearance/pre-flight inspection station. You must provide the following documentation to the CBP officer:
- Proof of Canadian citizenship;
- Letter from your prospective employer detailing items such as the professional capacity in which you will work in the United States, the purpose of your employment, your length of stay, and your educational qualifications; and
- Credentials evaluation (if applicable), together with any applicable fees.
If you are a Mexican citizen, then you are required to obtain a visa to enter the United States as a TN nonimmigrant. You should apply for a TN visa directly at a U.S. embassy or consulate in Mexico.
Once you are approved for a TN visa, you may apply for admission at certain CBP-designated U.S. ports of entry or at a designated pre-clearance/pre-flight inspection station. If a CBP officer finds you eligible for admission, then you will be admitted as a TN nonimmigrant.