The Washington State Department of Revenue determined that a telecommunications company’s leases of dark fiber were competitive telephone services and thus subject to retail sales tax. The taxpayer leased dark fiber – unused, unlit fiber optic cable – from various carriers and subsequently “lit” the dark fiber with its own equipment to provide telecommunications services to its own customers. The Department held that the leases of dark fiber were taxable competitive telephone services because dark fiber is a telecommunications “equipment or apparatus” under the plain meaning of those terms, and the taxpayer is a “consumer” of the services because it did not resell the leased dark fiber but instead “lit” the dark fiber to enable the transmission of voice and data communications, which the taxpayer then sold to its customers. The Department also held that dark fiber is not real property because it is not annexed to real property but is instead removable through various access points. In making its determination, the Department overruled a previous ruling involving a fiber optic cable purchase, Determination No. 97-157, which held that “telecommunications equipment or apparatus . . . is the apparatus that allows access to the telecommunications system, such as telephones or faxes,” to the extent it is inconsistent with the Department’s guidance in Excise Tax Advisory 3171.2012 (2012) or its current Determination, both holding that dark fiber is a competitive telephone service. Wash. Det. No. 13-0172R, 33 WTD 463 (2014).