256.411.5—Investment tax credit.
(a)
This account shall be debited with the amounts of investment tax credits related to service company property that are credited to account 255, Accumulated deferred investment tax credits, by service companies which do not apply the entire amount of the benefits of the investment credit as a reduction of the overall income tax expense in the year in which such credit is realized (see account 255).
(b)
This account shall be credited with the amounts debited to account 255 for proportionate amounts of tax credit deferrals allocated over the average useful life of property to which the tax credits relate or such lesser period of time as may be adopted by the service company.