The fact of the matter is;how are you going to use the aircraft?
Sounds to me like it`s only going to be transporting employees of the same company.Then you have to find out whether or not you will actually be making money flying this aircraft (for compensation or hire), though here it seems that since you`ll be flying non-paying passengers you`re just being an airborne company "busdriver".
Not quite sure how this works in your part of the world, but up North we divide operations in 3: commercial, private and club (i.e. flying club or school).
You`re not a commercial operator and you`re only moving people for the company - this goes under our "private" section, or perhaps "club" if you decide to organize a bit.get the picture?
Find out what kinds of operation you`ll be doing and find out what your country`s requirements are.