Dressing for a wedding reception is easier than you may think. All a man needs to do is wear a nice suit, which will be appropriate for the vast majority of weddings.
Follow the dress code
Some invitations will specify a dress code, for example, black tie or smart casual. This is your number one clue as to what to wear. If no dress code is specified, it is safest to ask the host what the dress code is. This is especially important in a non-traditional setting such as a beach wedding. In the case that you are unable to find out the dress code, it is most conservative to assume that the dress code is cocktail for an evening wedding.
The default wedding outfit
A safe option for a wedding is to wear a dark colored suit (black, navy and dark grey are all acceptable), a crisp white shirt, a tie, and black or brown polished dress shoes. This is what you should wear if the invitation says “cocktail” or “business casual”.
The black tie wedding outfit
Black tie is the most formal mode of dress you are likely to encounter in your life. Yes, there is white tie which is a step above black tie, but you are unlikely to ever be required to dress in white tie.
Your black tie wedding outfit should consist of a black tuxedo, black dress shoes, a white shirt and a black bowtie. You should wear a black waistcoat under your suit jacket.
A cummerbund (sash around the waist) is technically an acceptable alternative to a waistcoat, but these are rarely worn anymore. Never wear both a waistcoat and a cummerbund.
Technically, “semi formal” means the same as “black tie”, but often the host will write “semi formal” on the dress code while meaning something a little closer to cocktail wear. It is best to check with the host to ensure you are not overdressed or underdressed to the wedding.
Is it a daytime wedding?
For a daytime wedding, the dress code is more relaxed than that of an evening wedding. During the day, the dress code is usually lounge suit. Do not wear a tuxedo to a daytime wedding, unless the dress code specifies that it is a black tie event.