I have used Buildium and other screening and property management softwares in the past and never had something like this happen.

This is also programmed into our PM software, so it happens automatically.Our lease also states what rent will be applied and in what order and also a security deposit.So, you may want to check these documents to see if this is covered with your PMC.While we always try to be fair with our clients, we also have to generate enough income to pay our bills. 

If you use property management software like TenantCloud, you can enter your listing once and it will push it out to many websites simultaneously.

I'm a 33-year-old software engineer residing in the New York long island area.

It satisfies the basic requires though: We used a long-term lease for our state provided through Avail.co and then we amended it to specifically allow for sub-letting (easy to do with the software/website). 

The issues is time reviewing everything, we'll need all your documents and if we see a number wrong we can't go into the tax software to see what went wrong, it would be a lot of back and forth.

TenantCloud seems to be a hot topic, here is another posting about it.https://www.biggerpockets.com/...For 1 property I wouldn't even look at TC or any other software that charges a monthly fee.

My preference would be areas with tech workers, software professionals, etc. 

The software system we use is Propertyware but I know other systems like Appfolio have account keeping.  

It would be interesting to hear about the technology landlords use for leasing, property management software, unattended leasing, AI, deposits, and more.