Business formal attire is a phrase that is interpreted several different ways. The key to knowing what to wear to a formal business function is to understand the level of formality required at the event.
Dress Code Standards
The phrase business formal attire is generally interpreted by the level of dress formality required during the regular work day. If your company deems a crisp button up shirt and khakis to be the height of business dress, then this company would likely consider a business suit to be formal. If the company requires its employees to be buttoned and starched in professional business suits during the work week, then a formal occasion for them would likely be black tie. Generally speaking, when not obvious, a black tie event is announced on the invitation.
Levels of Formality
Here are a few defining phrase to help understand where your company measures up in the formality department.
Generally no dress code is in place. In a casual environment clothing is not considered important allowing the individual to wear whatever he or she feels is appropriate.
Though the name intimates anything goes, a strong sense of decorum should be followed. The word casual here simply means that the individual need not wear a suit. He or she is expected to project a professional image.
With a business professional dress code the company expects its employees to wear suits in relation to their job description.