Accounting question involving a property management company

[Soh Tanaka]

For some reason this tenant decided to pay the Jan 2020 rent at the end of Dec 2019 to the property management company. The owner received the rent (minus the fees) from the property management company in Jan 2020. Should the owner report the income in 2019 tax return or to the 2020 tax return?

Thanks,

Soh