Legal Question in Real Estate Law in Illinois

I assume that the company is renting the house from you.

Rent: a time estate in real property on a month to month basis.

Lease: contract for a time estate in real property. The time and conditions are stated in the lease.

Were they going to use the building as an office??? If not, it would seem that a company would only rent a house in order to rent it out again. The courts would hold that you had "constructive knowledge" if you knew they were not going to use it as office space. Willful ignorance is not going to work here. They are responsible for returning the property to you is the same condition as when they 'rented' it.

Are they renting or leasing? If rent there is no document and they can be evicted at the end of any rental period - no reason, good reason, or bad reason as long as laws are obeyed (equal opportunity).

If there is a contract then it is a lease and the terms of the contract/lease agreement govern. If the lease is silent on subleasing then usually the answer is no subleasing without permission.

The definition of a property manager would vary because the regulation is at a local level. Check your local ordinances.

I could be mistaken, but I understood your question to mean that you hired a company to find tenants for you. If this is the case, I am not aware of any exception which would allow them to do this without a real estate broker's license. Whether they can enter into a sublease would depend on the terms of your written agreement.