IRS Notice 2019-07 sets safe harbor rules for QBI deduction on rental real estate:
(A) Separate books and records are maintained to reflect income and expenses for each rental real estate enterprise;
(B) For taxable years beginning prior to January 1, 2023, 250 or more hours of rental services are performed (as described in this revenue procedure) per year with respect to the rental enterprise. For taxable years beginning after December 31, 2022, in any three of the five consecutive taxable years that end with the taxable year (or in each year for an enterprise held for less than five years), 250 or more hours of rental services are performed (as described in this revenue procedure) per year with respect to the rental real estate enterprise; and
(C) The taxpayer maintains contemporaneous records, including time reports, logs, or similar documents, regarding the following: (i) hours of all services performed; (ii) description of all services performed; (iii) dates on which such services were performed; and (iv) who performed the services. Such 8 records are to be made available for inspection at the request of the IRS. The contemporaneous records requirement will not apply to taxable years beginning prior to January 1, 2019.
Here is a link to IRS Notice 2019-07
