Short answer
The rule: a morning suit is for formal daytime ceremonies (before roughly four o’clock); a tuxedo is for evening. Everything else — the regional variants, the half-formal compromises — descends from that boundary. The honest modern answer: either is correct in its slot, and a bespoke cut makes both fit like nothing hired ever will.
Morning dress, properly
The morning coat with striped trousers, waistcoat and collar hierarchy is the point: it is the most formal daylight dress in the canon. It suits the traditional church ceremony and the grand garden party; it is also the most hired and worst-fitted garment in weddings, because its proportions are unforgiving. A pattern-cut morning coat is a different species from a hire one — the balance across shoulders and waistcoat is everything.
The tuxedo’s territory
From evening invitations onward: peak or shawl lapel, one button, no vent argument — the dinner suit is a uniform of restraint. Black-tie weddings simplify every other decision (see the guest guide) and the commission lives for decades of invitations afterwards. Midnight blue photographs darker-than-black under camera flash — a connoisseur’s detail worth asking the tailor about.
Choosing between them
Read the invitation’s time and venue, then the couple’s register: church at two in the afternoon argues morning dress; ballroom at seven argues black tie. Between them lies the practical modern majority — the late-afternoon ceremony — where a sharp dark two-piece or the couple’s stated dress code settles it. When you control the code, choose by venue light and photographs.
Planning a real wedding? The house fits grooms and their parties across Europe on the proposed 2027 programme — bring the date and the venue photographs to the first fitting, and the calendar is planned backwards from the day.