What must licensees include on all advertisements and business cards?

The requirement for licensees to include a unique identifier on all advertisements and business cards is rooted in the need for transparency and accountability within the mortgage industry. The unique identifier serves as a means to verify the licensee's credentials and provides consumers with an easy way to find information about the individual and their licensing status. This measure helps to ensure that potential clients can confirm that they are dealing with a qualified and registered professional, thereby fostering consumer trust and promoting ethical practices within the industry.

In contrast, while an office address, phone number, and company logo are useful components of marketing materials, they are not mandated under the same regulatory requirements as the unique identifier. Therefore, including a unique identifier is crucial to comply with licensing regulations and to enhance consumer protection, making it the correct answer for what must be included on advertisements and business cards.