Which of the following indicates a violation of cosmetology practice?

Performing services without a license is a clear indication of a violation of cosmetology practice because licensure is a legal requirement for all beauty professionals, including those providing eyelash extension services. Licensing ensures that practitioners have undergone the necessary training and education to perform procedures safely and effectively. It serves to protect consumers from unqualified individuals who may not adhere to industry standards or safety protocols.

In contrast, continuing education enhances a professional's skills and knowledge, while using licensed products ensures that the materials being applied meet safety and efficacy standards. Setting up a home salon, while it may require specific permits or adherence to zoning laws, does not intrinsically violate cosmetology rules as long as the services are being performed by a licensed professional. Therefore, it is essential for practitioners to maintain their licensing and operate within the legal framework established for the industry.