I also signed up under the National CREIA (Real Estate Investment Club) and I get quarterly refund gift cards directly from HD.

I had only 2 properties for the 1st quarter of 2018,   only 3 by the half of the year,  and ONLY recently did I add properties #4,5 and October #6 property.    

The property has 5 bedroom units, each with a private bathroom, with 1 of the units being an owner quarter.

@Joe WoodYou are normally required to pay estimated taxes throughout the year to avoid the penalty for failure to make estimated tax payments.Did you make estimated tax payments in the 1st, 2nd and 3rd quarter?

At Your Castle Real Estate's quarterly meeting we had a presentation on the economics of supply and demand in the Airbnb market.

Sure at 10 doors that might be easy, but at 100, having even a quarter of your door count dictating how you run your business as opposed to 100% of the doors you manage follow the same process is going to hurt your margin and make it so your margin looks like its at 75 doors anyway.

I have personally set a goal to buy a rental property each quarter this year.

With the first three quarters completed, we anticipate having less than 20% of our portfolio experience a vacancy for the 6th year in row.  

Kent MI for example, home to Grand Rapids, charges a quarter per record per year, and this is before they get filtered by amount owed and years delinquent.

Quarterly I am honestly not so sure about but like I said in my OP, I am open to suggestions.