Which of the following would DEFINITELY require a license if the person is not an employee?

Acting as a property manager definitely requires a real estate license when the individual is not an employee. Property management involves leasing, renting, or maintaining properties for others, which is considered real estate activity as defined by state laws. Since property managers typically engage with the public on behalf of property owners and handle financial transactions, a license ensures that they adhere to legal and ethical standards within the industry.

On the other hand, collecting rent on behalf of a landlord might not always require a license if the collector is an employee of the landlord. Managing one personally owned property does not require a license because it does not involve public representation or management of another's property. While signing contracts with clients may require a license, it depends on the context and the nature of the contract. Thus, acting as a property manager stands out as the clear activity that necessitates a license when performed by someone who is not an employee.