Although this is the easiest dress code with which to comply it’s necessary to sound a note of caution.
While most men will already own a lounge suit that could be worn to a wedding, few will own one that should to be worn to a wedding. The reason is that a man, whether he’s a guest or the groom, should look like he’s dressed up for a celebration, not for a day in the office.
His suit should look spruce, rather than well-worn, and say something positive about its owner, rather than speaking of the daily grind. To look the part consider going for a fabric that’s got a bit of life to it, like a mohair, in a shade lighter than you’d wear to work, give some thought to a check (Google Steve McQueen in The Thomas Crown Affair if you harbour doubts about checked suits) and contemplate a three-piece suit, or peak lapels on a single-breasted suit.
The resulting suit will be perfect for drinks parties and dinner dates. A shirt with a white collar and cuffs, a heavy silk tie, a pocket square and a pair of espresso-brown oxford shoes will ensure you look the business, rather than dressed for business.