Safe harbour option requires Form 3CEFB filing and officer verification, with review and potential invalidation on specified grounds. The rule requires an assessee to furnish Form 3CEFB to elect the safe harbour option; the Assessing Officer must verify eligibility of the assessee and the specified domestic transaction and may seek further information. If the assessee does not comply, or the officer finds ineligibility or tariff nonconformity, the Assessing Officer may, after hearing, declare the option invalid by written order. The assessee may object to that order to the subordinate Principal Commissioner/Commissioner or Principal Director/Director, who after hearing will decide; specified statutory time limits govern these orders and failure to act within them renders the option valid.