(a) An adjustment under the circumstances stated in paragraph (b) of § 1.1312-3 (relating to the double exclusion of an item of gross income) which would result in an additional assessment, is authorized only if assessment of a deficiency against the taxpayer or related taxpayer for the taxable year in which the item is includible was not barred by any law or rule of law at the time the Commissioner first maintained, in a notice of deficiency sent pursuant to section 6212 (or section 272(a) of the Internal Revenue Code of 1939) or before the Tax Court of the United States, that the item described in paragraph (b) of § 1.1312-3 should be included in the gross income of the taxpayer in the taxable year to which the determination relates.

(b) An adjustment under the circumstances stated in § 1.1312-4 (relating to the double disallowance of a deduction or credit), which would result in the allowance of a credit or refund, is authorized only if a credit or refund to the taxpayer or related taxpayer, attributable to such adjustment, was not barred by any law or rule of law when the taxpayer first maintained in writing before the Commissioner or the Tax Court that he was entitled to such deduction or credit for the taxable year to which the determination relates. The taxpayer will be considered to have first maintained in writing before the Commissioner or the Tax Court that he was entitled to such deduction or credit when he first formally asserts his right to such deduction or credit as, for example, in a return, in a claim for refund, or in a petition (or an amended petition) before the Tax Court.

(c) Under the circumstances of adjustment with respect to which the conditions stated in this section are applicable, the conditions stated in § 1.1311(b)-1 (maintenance of an inconsistent position) are not required. See paragraph (b) of § 1.1312-3 and § 1.1312-4 for examples of the application of this section.