Choose the dress code based on three factors: the event type, the audience and the company culture. A formal gala or starred dinner calls for Black Tie. For a conference or client dinner, Business Formal fits. For a kick-off or brainstorm day, Smart Casual is enough.
Always communicate the dress code clearly in the invitation. Many people are unsure what's expected. A brief explanation of less familiar codes is always appreciated. Live Impact advises based on your concept.