Applicant offers to pre-pay a year's rent in cash

[Astrid Dymond]

I just had a prospective tenant tell me that he would want to pre-pay the yearly rental fee in cash upfront because "that is just the way he does business."  My gut tells me that this is a red flag.  I would still screen this applicant.  Is it ok to accept the yearly rent upfront in cash? What are the potential pitfalls?