Forty-five percent of the total sales price for the sale of a modular dwelling unit is exempt from sales tax when the modular dwelling unit is built at a production facility and moved in whole or in parts, to be assembled on site, and permanently affixed to the real property and used for residential or commercial purposes. For purposes of this exemption a "modular dwelling unit" means a structure that is not subject to the motor vehicle excise tax imposed pursuant to Section 2103 of Title 68.
Okla. Admin. Code § 710:65-13-450