(2) Leaseback. A section 467 rental agreement is a leaseback if the lessee (or a related person) had any interest (other than a de minimis interest) in the property at any time during the two-year period ending on the agreement date. For this purpose, interests in property include options and agreements to purchase the property (whether or not the lessee or related person was considered the owner of the property for Federal income tax purposes) and, in the case of subleased property, any interest as a sublessor.
26 CFR § 1.467-3
General rule. Under 1.467-1(d)(2)(i), constant rental accrual (as described under paragraph (d) of this section) must be used to determine the fixed rent for each rental period in the lease term if the section 467 rental agreement is a disqualified leaseback or long-term agreement within the meaning of paragraph (b) of this section. Constant rental accrual may not be used in the absence of a determination by the Commissioner, pursuant to paragraph (b)(1)(ii) of this section, that the rental agreement is disqualified. Such determination may be made either on a case-by-case basis or in regulations or other guidance published by the Commissioner (see 601.601(d)(2) of this chapter) providing that a certain type or class of leaseback or long-term agreement will be treated as disqualified and subject to constant rental accrual.