Change in Accounting Method Form 3115:
Form 3115, Change in Accounting Method, is used to correct most other depreciation errors, including the omission of depreciation. If you forget to take depreciation on an asset, the IRS treats this as the adoption of an incorrect method of accounting, which may only be corrected by filing Form 3115. When changing methods of accounting from not taking depreciation (incorrect method) to taking depreciation (correct method) use Code 7 on Form 3115 if the asset is still in use, code 107 if disposed.

The IRS’s automatic consent procedures for taxpayers who have adopted an impermissible method of accounting for depreciation (or amortization) and have either claimed no allowable depreciation, less depreciation than allowable, or more depreciation than allowable is provided in the guidance at Rev. Proc. 2015-13 and 2018-31.

Generally, Form 3115 must be attached to the taxpayer’s tax return for the year of change by the original due date (including extensions). A copy must also be filed with the IRS no later than when the original is filed with the taxpayer’s return.

Taxpayers who qualify under the automatic procedure are permitted to change to a method of accounting under which the allowable amount of depreciation is claimed. The unclaimed depreciation from years prior to the year of change is taken into account as a net negative (taxpayer favorable) adjustment in the year of change, generally effective for tax years ending on or after December 31, 2001 and are deducted in full on the return for the year of change.