Group travel and citizenship evidence, the employment explanation, and credentials so they can be retrieved easily. Include route-specific materials such as an applicable visa or petition approval. Check current official instructions rather than treating a generic packing list as complete.
Keep one accurate final version
Confirm that dates and employer names agree and that any translations or evaluations correspond to the documents presented. Save a copy of what you carry, including relevant earlier approvals, for follow-up questions. Ask the employer who can clarify an unexpected factual issue during the travel window.
Do not place outdated drafts beside the final letter without an explanation; contradictory versions can create a question that careful preparation could have resolved. Version discipline matters most when something changes late. Withdraw the superseded letter, evaluation or offer amendment from the carried file and hold it in a separate archive marked with the date it was replaced, so the packet presented at inspection gives exactly one answer to each question.
Hypothetical example: a chemist’s employer reissues the letter to correct the laboratory address after the first version has been printed, and both copies travel in the same folder, inviting a question about where the work actually happens. Where a translation or credential evaluation was prepared against the earlier version, ask whether it still describes the document it now accompanies, because the mismatch is easier to fix at home than in the inspection line.