Closed on First Out of State SFR - Screening Question

[Derek Luttrell]

Hey Everyone, 

I closed on my first out of state rental today--it's my hometown in Indiana, but I live in Chicago now. My dad is still in this town.

Anyway, I put up an online ad yesterday, had my closing at 9:00 a.m. this morning, and then had 4 showings/applicants at noon today. One told me that it will be her, her husband, their young grandson, and that her adult daughter and her boyfriend plan to move into town and stay with her "while establishing themselves." I told her that every adult occupant needs to fill out the application and be screened, and she said that "doesn't know when they're actually moving in," and it would be difficult and time-consuming to get them to fill out the application. Because of this, she wants to apply just with her and her husband. 

Am I right in thinking that this is not an acceptable request? Even if she doesn't know when exactly they're moving in, if it's a possibility at all, I'm allowed to require that they apply beforehand, right?