The safe harbor doesn’t apply to property leased under a triple net lease or personally used by the owner for the greater of 14 days or 10% of the days rented. Users of the safe harbor must meet strict recordkeeping requirements. Contemporaneous records must detail hours, dates and descriptions of the services, and who performed them. If the services are done by contractors or employees, the taxpayer must keep logs of the work done by them, as well as proof of payment. Taxpayers must also attach a statement to their tax return for each year in which they use the safe harbor. See Rev. Proc. 2019-38 for what to include. Special rules apply to taxpayers who own multiple rental properties. They can treat each property separately or they can aggregate similar rental activities into commercial or residential categories. Commercial real estate can be aggregated only with other commercial realty. Ditto for residential rentals. Mixed-use property, such as a building with residential and commercial tenants, may be treated as a separate rental activity or bifurcated into commercial and residential property.