I do a lot of compliance shops with various companies, and am required to keep a picture ID on file. They are some of my easiest shops to perform and report, and pay well, considering the amount of work you do.
It's not exactly an unknown person, it's a company, and most of the MS company sites are secured sites.
It might help if you post the company name, as others may be able to tell you if it is a reputable company or not.
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Plan the work. Work the plan.