The TN visa is a consular process, not a border formality. If you have heard someone say they got "approved at the border," that description does not apply to Mexican nationals. Your case is reviewed and decided at a U.S. Consulate in Mexico, and only after your visa is issued do you present yourself at the port of entry to begin your status. Knowing each step, and roughly how long it takes, helps you plan your notice period, your travel, and your first weeks in a new role with less uncertainty.
The Seven Steps
Your employer issues a compliant job offer and support letter
Before anything else happens, your future employer prepares two documents: the job offer letter and the support letter for the consulate. These describe your duties, your compensation, and how your role and your degree map to the Engineer professional category under Chapter 16 of USMCA. Which attorney drafts and reviews these letters depends on the employer. Some manufacturers use their own immigration counsel; others ask the recruiting side to coordinate that review. Either way, these two letters are what the consular officer reads most closely, so getting them right matters more than getting them fast.
You assemble your document package
While the offer and support letters are being finalized, you gather your side of the file. The full checklist is below, but the short version is your passport, your degree, your professional license status, your transcript, an updated CV, and proof of your work history. Your CV and your visa application need to tell one consistent employment story. Gaps or dates that do not line up get questioned at the window, not fixed afterward, so this is the moment to clean them up.
You complete the DS-160 form
The DS-160 is the formal U.S. nonimmigrant visa application, completed online ahead of your interview. It asks for detailed travel history, employment history, and personal information. Inconsistencies with your CV or supporting documents tend to surface right here, so treat the DS-160 as part of the same document review as everything else, not a formality at the end.
You pay the fees and schedule your consular appointment
Two government fees apply on the candidate side: the DS-160 application fee of $185, and once your visa is approved, the reciprocity fee of $382 for a four-year stamp. Who covers these varies by employer. Some employers reimburse candidates as part of the offer; others do not, and the candidate pays them directly. Confirm which applies to your offer early rather than assuming either way. Appointment availability at the consulate, more than paperwork, is usually the biggest driver of how long this stage takes.
You attend the consular interview
A consular officer reviews your documents and asks about your role, your degree, and your ties to Mexico. The most common reasons a case runs into trouble here are a mismatch between your degree and the job duties, prior immigration history such as a previous H-1B or a close family member with a green card, past visa violations or a criminal record, and thin evidence of ties back home. None of these get fixed in the interview room, which is why the document and job description review earlier in the process matters as much as it does.
Your visa is issued
If approved, your passport is stamped with a TN visa valid for up to four years. The stamp is what lets you present yourself for entry. It is not your status yet; that is determined at the port of entry.
You enter the U.S. and your TN status begins
At the port of entry, a Customs and Border Protection officer reviews your visa and documents and admits you into TN status, typically for up to three years at a time. TN status renews indefinitely as long as you continue to qualify and continue working in the approved role. Counting from your first interview with the employer to your actual start date, most candidates should expect four to six months once the offer, the document review, and consulate scheduling are all accounted for.
You may hear that TN visas get "approved at the border." That is not how it works for Mexican nationals. Your case is decided at a U.S. Consulate in Mexico before you travel. The port of entry step is about presenting a visa that has already been issued, not making your case for the first time.
What You Need to Prepare
Valid Passport Critical
Check the expiration date before anything else. A passport expiring within twelve months can block the filing regardless of how strong the rest of your file is.
University Degree (Título Universitario)
Your degree in a recognized engineering discipline. This is the foundation of your case for the Engineer category.
Professional License (Cédula Profesional)
A cédula in process is acceptable at this stage. It does not need to be issued before you begin the visa process.
Official Transcript (Kardex or Historial Académico)
Your official academic record, confirming the coursework behind your degree.
Updated CV
One clean employment history with no overlapping or contradictory dates. This is the document the consular officer and your future employer both read most closely.
Letters of Recommendation or Employment Verification
Documentation that backs up the roles and dates on your CV.
Relevant Certifications
Any certifications tied to your discipline, such as quality, IATF, or process-specific credentials.
Where Cases Run Into Trouble
Degree-job mismatch
Since June 2025, engineer TN applicants must hold a degree in a recognized engineering discipline. A computer science or software degree no longer qualifies for the Engineer category, so the mapping between your degree and the offered role has to be exact.
A vague job description
A job description that lists only "Bachelor's degree or higher" without naming a discipline, or that reads as general supervision rather than engineering judgement, is a denial risk before you ever sit for the interview. This is on the employer's side of the file, but it affects your outcome directly.
Prior immigration history
A previous H-1B, a pending green card process, or a close family member with a green card can complicate a TN case. Disclose it and have it reviewed early, not discovered at the window.
An inconsistent employment history
Your CV and your DS-160 need to match. Overlapping dates or unexplained gaps get fixed before filing, not discovered at the consulate.
Before You Start
Most of the delay in a TN case sits outside your control, in consulate scheduling. Most of the risk sits inside it: a document that does not match, a passport close to expiry, a history that was not disclosed. Get your file clean before the offer arrives, ask early who covers the fees, and treat every date on your CV as something an officer will check.
This article is informational only. ACE & Bridgewell is not an immigration law firm and does not provide legal advice. TN visa requirements can change and individual circumstances vary. Always work with a qualified immigration attorney for guidance specific to your situation.
