Black tie is a dress code for men that consists of the traditional tuxedo and its accompaniments which includes: a black dinner jacket, matching trousers, white formal shirt, a black bow tie or long black tie, optional black waistcoat or cummerbund, black dress socks, and formal shoes. A white dinner jacket can be substituted in hot weather.

A black self-tie silk bow tie which matches the lapel facings is most common, however, a long black silk tie is becoming a popular alternative.

The best option for shoes is a pair of black leather oxfords. An alternative would be a pair of black derby shoes. Men should avoid wearing brown shoes with a black suit to a black tie optional event because this pairing is informal.

Black tie events are formal affairs that require you to be suitably dressed. Men should refrain from wearing light coloured suits and outfits that don't include a tie. Wearing a blazer with mismatched trousers, patterned ties or shirts and no tie is simply too casual and informal for this type of event. Whether you opt for a bow tie or regular tie, you must wear one. You should't wear casual clothing such as jeans, T-shirts, shorts, jumpers and trainers. It's also best to avoid suits that aren't black or dark blue.

Black-tie attire for women traditionally indicated a floor-length gown in a formal fabric, like silk charmeuse, chiffon, or Mikado, embellished with Alencon lace, embroidery or crystals.