1. Wearing a suit and tie can be complemented by a waistcoat, but it is not a strict requirement. Typically associated with formal events, a waistcoat adds a touch of elegance to a suit ensemble.2. Nonetheless, it is not mandatory to wear a waistcoat with every suit. In certain settings, wearing a single-button or double-button suit may suffice without a waistcoat, maintaining a professional and formal appearance.3. The primary purpose of a waistcoat is to add depth and a sense of sophistication to an outfit. If you choose to forego the waistcoat, ensure that there is a harmonious transition between your shirt collar and the suit jacket lapels to preserve a polished and professional look.4. Ultimately, whether or not to wear a waistcoat with a suit is a matter of personal style, the formality of the occasion, and personal comfort. For formal business events, wearing a suit with a waistcoat is often considered more appropriate according to etiquette.