§ 6233. Extension to entities filing partnership returns, etc.

(a) General rule
If a partnership return is filed by an entity for a taxable year but it is determined that the entity is not a partnership for such year, then, to the extent provided in regulations, the provisions of this subchapter are hereby extended in respect of such year to such entity and its items and to persons holding an interest in such entity.
(b) Similar rules in certain cases
If a partnership return is filed for any taxable year but it is determined that there is no entity for such taxable year, to the extent provided in regulations, rules similar to the rules of subsection (a) shall apply.