Hal_Al
Level 15

Get your taxes done using TurboTax

The mortgage payoff is irrelevant. The $300,000 net proceeds is irrelevant. What's relevant is the capital gain. Net sales price (after expenses, but not mortgage) less cost basis.  Then comes "depreciation recapture", an increase in your capital gain, but taxed at a different rate.

 

In determing how to report the split, you usually follow the money.  As tagteam said, more info is needed.