If I Airbnb the 2nd BR in my 2BR condo the whole year, I occupy the 1st BR Jan-Sept, and then Airbnb the 1st BR October-December, how do I expense each part of the year?

[Anonymous]

Assume I own a 1,000 square foot condo with 2 bedrooms of 200 square feet each that is owner occupied (i.e., I live in it).  

I will rent the 2nd bedroom on Airbnb to multiple guests throughout the year who will have full access and privileges to the 600 square feet of common areas for laundry, kitchen, etc.  The guests in the 2d bedroom will share common areas with me for January-September, and with other Airbnb guests in the 1st bedroom from October-December when I will not be occupying the 1st bedroom.

From all that I have seen, it seems that only 20% of expenses (HOA, mortgage interest, taxes, etc.) would be deductible against Airbnb income for the 2d bedroom for January - September while I am in the 1st bedroom.  

For October-December would 100% of expenses be deductible against Airbnb income since I am no longer in the 1st bedroom and it is now 2 Airbnb guests occupying/sharing the whole condo?

If so, that seems like a windfall to the IRS of 30% of expenses not being able to offset income for January-September.  Is there any way or authority to better match the Airbnb income for January-September with the actual expenses of having 2 people in the condo?

I file on Schedule C for my Airbnb activities.

 Thank you!

[KittyM · Accepted solution]

You cannot write off the expenses of the common areas to which your Airbnb guests did not have "full and exclusive" use.  Since you were also using the common areas during the first part of the year, their use was not exclusive and you are not qualified to take expenses on those spaces for that time.  If you rent the condo for all of 2019, and have no personal use, then the deduction for 2019 would not be limited by this factor.