Prepare the factual position description, pay, and intended period, together with the applicant's qualification and identity records. Any meaningful difference between the offer and the proposed support letter should be resolved before signature.
Let each party confirm only what it actually knows
The applicant supplies credential and identity evidence, while the employer confirms the real terms of employment. If a staffing agency and a client describe the assignment differently, ask them to reconcile the discrepancy rather than picking whichever version sounds cleaner. Keep dated versions of every document so the current one is clearly identified.
Ask the hospital's recruiter for a letter on letterhead that names the legal employing entity, states that the applicant is being engaged as a Registered Nurse under the USMCA, and describes the unit and duties in clinical terms. Start from the contract: list the deliverables, the on-site duration and the client’s obligations, then have the Canadian corporation issue a letter that repeats those facts in the language of the Computer Systems Analyst listing. Costs attach differently: the employer's drafting time is internal, while retrieving a diploma from an institution abroad is a personal expense someone must agree to cover.