(a) If a taxpayer's method of accounting for Federal income tax purposes is changed, the accounting method employed in determining entire net income for purposes of article 9-A of the Tax Law must be changed at the same time to the method approved for Federal income tax purposes. When a change of accounting method occurs, any adjustments which are determined to be necessary solely by reason of the change in order to prevent amounts from being duplicated or omitted must be taken into account to the extent they are required to be taken into account in determining the taxpayer's Federal taxable income.

(b) A taxpayer whose method of accounting is changed must submit, with its first report in which the new accounting method is used, a copy of the consent of the Commissioner of Internal Revenue, together with complete details of any adjustments with respect to items of income or deduction.