An offer letter does not itself authorize work, but it can help show whether a proposed role fits an existing employer-specific permission. Review the underlying status, approval notices, I-94 and any employment authorization document together. Different visa and I-94 expiry dates are not automatically errors because the documents serve different functions; investigate an actual inconsistency before relying on it.
Building a small evidence file before the first payroll date
Assemble the passport biographic page, every visa foil, the current I-94 printout, prior approval notices and any employment authorization document, then list the dates side by side. For the Gold Card filing itself, follow the instructions issued through the official portal for supporting documents. Missing items do not automatically end a case, but they can prompt a request for evidence or a refusal, so gaps are worth closing early.
Hypothetical example: a clinical laboratory courier network onboards a new worker from the passport visa alone, because the visa foil is the document its coordinator recognises. The visa records permission to seek admission; the admission record shows what was actually granted and until when, and the two answer different questions. Where an employer asks for the wrong document, supply what is asked for and the admission record together rather than arguing about which is correct.
Keep a dated copy of everything provided at onboarding, because a payroll file assembled in a hurry is difficult to reconstruct months later when someone questions a start date.