@michaeljd wrote:
.....the rental property itself was never reported as an asset either.
You need to file Form 3115 to catch up on the foregone depreciation.
You adopted an impermissible method of accounting when you failed to begin depreciation deductions three years ago. As a result, you cannot amend because you used that impermissible method in two or more consecutively filed tax returns.
See https://www.irs.gov/publications/p946#en_US_2020_publink1000107386
Seek professional guidance for assistance with filing Form 3115.
