Kentucky Revised Statutes Title XI. Revenue and Taxation § 136.540.Calculation of payroll factor

(a) The employee's services are performed entirely within this Commonwealth.

(b) The employee's services are performed both within and without the Commonwealth, but the service performed without the Commonwealth is incidental to the employee's service within the Commonwealth. The term “incidental” means any service which is temporary or transitory in nature, or which is rendered in connection with an isolated transaction.

(c) If the employee's services are performed both within and without this Commonwealth, the employee's compensation will be attributed to this Commonwealth if:

1. The employee's principal base of operations is within this Commonwealth;

2. There is no principal base of operations in any state in which some part of the services are performed, but the place from which the services are directed or controlled is in this Commonwealth; or

3. The principal base of operations and the place from which the services are directed or controlled are not in any state in which some part of the service is performed but the employee's residence is in this Commonwealth.