Holding Deposit for prospective tenant for 1 month, good idea?

[Jessica Markley]

Newbie here, 1st rental listed but have done rehabs/flips before. I have an interested tenant, they pass qualifications on all standards except background check which isn't complete yet pending formal application (using Cozy.) However, their current lease isn't up until end of Feb 2020. My single family rental is move-in ready now available Feb 1. Would it make sense to have them pay a holding deposit (if so how much?) to hold the property for a month? It was my understanding that holding beyond 2 weeks w/o a security deposit etc might not be smart but what if I was able to charge a "holding deposit" for month of Feb that would cover the mortgage etc if they walk and don't move forward. I would apply "holding deposit" to security deposit assuming they sign lease. Any thoughts or suggestions here? Anyone done this and are there good forms out there for this? I'm in western suburbs of Chicago if that's helpful.