Okla. Stat. tit. 40 § 1-209
All individuals performing services within this state for any employing unit which maintains two or more separate establishments within this state shall be deemed to be employed by a single employing unit for all the purposes of the Employment Security Act of 1980, except as provided under paragraphs 10 and 11 of Section 1-208 of this title.
Whenever any employing unit contracts with or has under it any contractor or subcontractor for any employment, which is part of its usual trade, occupation, profession, or business, unless the employing unit as well as each such contractor or subcontractor is an employer by reason of Section 1-208 or Section 3-203 of this title, the employing unit shall for all the purposes of the Employment Security Act of 1980 be deemed to employ each individual in the employ of each such contractor or subcontractor for each day during which such individual is engaged in performing such employment; except that each such contractor or subcontractor who is an employer by reason of Section 1-208 or Section 3-203 of this title shall alone be liable for the contributions measured by wages paid to individuals employed by the contractor or subcontractor, and except that any employing unit which shall become liable for and pay contributions with respect to individuals in the employ of any such contractor or subcontractor who is not an employer by reason of Section 1-208 or Section 3-203 of this title may recover the same from such contractor or subcontractor.
Each individual employed to perform or to assist in performing the work of any agent or employee of an employing unit shall be deemed to be employed by such employing unit for all the purposes of the Employment Security Act of 1980, whether such individual was hired or paid directly by such employing unit or by such agent or employee of an employing unit, provided the employing unit had actual or constructive knowledge of the employment.
Okla. Stat. tit. 40, § 1-209