Investors & landlords

Thank you! Need to digest the info you provided, but - we've owned this one rental house for 16 years, and every year have reported rent and expenses on Schedule C, not Schedule E. Is there anything we can/should do about that now, or is it too late because it's been so many years and now the home is sold? Sounds like we should still use Form 4797 which we'll figure out. Thank you again!