I am filing out taxes for my rental property in Philadelphia, PA which I own as an individual. As far as I can tell, all applicable taxes specifically for Philadelphia are the following:

• School Income Tax (SIT)
• Net Profits Tax (NPT)
• Business Income & Receipts Tax (BIRT)

Am I understanding all of these taxes correctly? Do they stack together? Also, are they on net rental income? Since I only started renting it out later in the year, the net (less mortgage interest, insurance, etc...) is actually negative. Does this mean I can simply not file them?