All employers and self-employed individuals residing or having their places of business outside of the City of Reading but who perform services of any type or kind or engage in any occupation or profession within the City of Reading do, by virtue thereof, agree to be bound by and subject themselves to the provisions, penalties and regulations promulgated under this Part with the same force and effect as though they were residents of the City of Reading. Further, any individual engaged in an occupation within the City of Reading and an employee of a nonresidential employer may, for the purpose of this Part, be considered a self-employed person, and in the event his or her tax is not paid, the City of Reading shall have the option of proceeding against either the employer or employee for the collection of this tax as hereinafter provided.