In order to make sure your jeans are formal enough, you will want to lean toward formal and classy with your choice of shirt and jacket. A crisp dress shirt is always a good choice when paired with jeans, add a sporty button-up shirt can add a dash of personality to a more casual business office.

Traditionally, jeans are classified as casual or "workwear" and are not considered appropriate for strictly "Formal" (White Tie or Black Tie) or even "Semi-Formal" events. However, in the modern era of "Business Casual" and "Smart Casual," dark-wash, well-fitted jeans can sometimes pass for an upscale event if styled correctly. To pull this off, the denim must be a solid, deep indigo or black, completely free of distress, holes, or fading. You must pair them with formal elements: a tailored blazer, a crisp dress shirt (tucked in), and high-quality leather shoes like Oxfords or Chelsea boots. While this look might fly at a tech industry gala, a trendy wedding, or a nice dinner, it remains a "fashion risk." If an invitation explicitly states "Formal," it is a social faux pas to wear denim. In those cases, you should stick to wool trousers or a suit. Jeans are inherently a rebellious choice in the world of high etiquette, signifying a relaxed attitude that clashes with the ceremonial nature of true formal wear.