How To Screen Self Employed Tenants...?

[Robert Smith]

I have a couple who have applied for one of my rental properties (3bed, 2bath sfh) through Cozy and claim they are self employed and make $80,000/mo each and they are willing to pay for an entire year worth of rent. The credit score for one of the applicants is in the mid 700s and the other applicant is low 500s. They currently live out of state as well.

My question is, what questions should you ask to verify this person actually makes that much, and their business is legal, and how realistic is it for most applicants to be willing to pay a full year up front? 

It sounds a bit too good to be true, I'd hate to caught up in some illegal scheme. 

Thanks