Before the experience history is assessed against it and before any filing or admission step relies on the agreement. If the client changes the project, reassess whether the specialty connection and offered professional work remain accurate.
Keep scope and evidence on the same version
Retain a dated agreement and record changes. A reference package tailored to an earlier project may no longer explain the current one. Confirm the final scope and effective work authorization before starting the engagement in the United States.
Once the structure is decided, the letter and agreement are final, and the admission step has actually succeeded. A first review should create a dated sequence from the signed offer through the chosen admission or petition step, travel, and the first lawful workday. Once accurate evidence is ready, a Canadian may seek TN admission at a port of entry, or the employer may file Form I-129 where appropriate. TN admission can be granted for up to three years at a time, so a one-year contract with an expected renewal should be presented as such, and a new application follows each contract extension rather than being assumed. TN admission is granted for a defined period supported by the employer's letter, and a letter that declines to name an end date invites the officer to ask what temporary means here.