I agree with the "choose your battles" remark from Russell, and I'll add that I am sure that while it really helps many people who truly need their animals, many people abuse the ESA stuff. 

You cannot deny them because you don't want an animal on the property.

Even a contractor with 30+ years of experience only knows what they know - so, they may not know the most cost-effective solution:(5) Political trends that may lead to more controls on landlords - being forced to accept S8, not being able to deny for evictions, rent control, etc.

If they provide sketchy information, deny their application and move on.

This is the simplest method, but it also means your tenants are more likely to abuse the utilities by leaving windows open with the heat or A/C running, leaving lights on, ignoring the toilet that constantly flushes on its own, etc.3.

I don't have the option to deny an application just because they have a voucher, but even if I wasn't required, I am happy to have a voucher holder in a C neighborhood, and with a little effort, I almost always get paid what I am owed. 

Otherwise, should something go wrong, the insurance company may deny any claims. 

Supply house took windows back pending any credit from manufacturer , it was denied all the paperwork was correct .

-Cedric Deny her.

We will likely deny him and serve them notice again, as I always see him when I'm up there.