The dress line on an invitation tells you how formal to be. With no dress line, wear a lounge suit: a suit and tie.
- Checked on 22 October 2026
- Sources: Swiss Protocol Regulations, Canadian Heritage, Debrett’s
In short
- No dress line: lounge suit.
- White tie: tailcoat and white bow tie. Evening only.
- Morning dress: morning coat. Day only.
- Black tie: dinner jacket and black bow tie. Evening only.
- Lounge suit, business suit and dark suit are one code.
- Swiss credentials and New Year greetings: dark suit, national dress or uniform.
- National dress can replace any code.
Our outfit helper opens set to a wedding guest in a lounge suit. Menswear only, for now.
The codes, from the most formal to the least
More formal
- White tieEvening onlyDE FrackFR cravate blancheIT frac
- Morning dressDay onlyDE CutFR jaquetteIT tight
The formal code for the day.
- Black tieEvening onlyDE SmokingFR smoking, cravate noireIT smoking
- Lounge suitDay or eveningDE dunkler AnzugFR tenue de villeIT abito scuro
Also called dark suit or business suit. The default when the invitation says nothing. Swiss ceremonies: dark suit, national dress or uniform.
- Smart casualDay or evening
Debrett’s: “the hardest dress code to interpret”.
Less formal
Can replace any code, at the same level.
What each code means
| Code | Men | Women |
|---|---|---|
| White tieEvening only | Black tailcoat, black trousers with braid, white wing-collar shirt, white waistcoat and white bow tie | Full-length evening dress |
| Morning dressDay only | Black or grey morning coat, grey or striped trousers, waistcoat, tie | A dress or skirt with a jacket. Hats are usual, especially at weddings. |
| Black tieEvening only | Black or midnight blue dinner jacket with silk lapels, white evening shirt, black hand-tied bow tie | An evening dress or skirt. On the length, see below. |
| Lounge suitDay or evening. Also dark suit or business suit. | A suit, a shirt with a turndown collar (not a button-down) and a tie | By day: a day dress, a trouser suit, or a skirt and jacket. In the evening: a smart or cocktail dress with sleeves or a jacket. |
| Smart casualDay or evening | A jacket or blazer; flannels, cords or chinos, not jeans; a shirt with a collar; smart shoes. No trainers. | A smart day dress with a jacket. No sports clothes or trainers. |
| National dressIn place of any code | Your national dress, at the same level | The same |
The times follow Canadian Heritage: white tie and black tie are “never worn during the day”. Debrett’s adds: “Morning dress should not be specified to be worn at an event starting after 6pm.”
The outfit helper shows black tie, the lounge suit, the Swiss dark suit and smart casual, for men. It has no white tie, morning dress or national dress yet.
No dress line? Wear a lounge suit
Canadian Heritage: “If the invitation contains no indication in this regard, lounge suit is assumed to be appropriate.” And: “The more important the ceremony, the darker the suit.”
Debrett’s: “‘Lounge suit’ is an expression only seen on invitations.” In conversation, people say dark suit or business suit.
“Informal” does not mean casual
In the Canadian guide, “Informal wear” means “Suit and tie”. Its French version calls it “Tenue de ville”. Casual clothes have their own heading.
Black tie: how long is the dress?
Sources disagree
Debrett’s dress code guide: “long, or at least not very short, is usually best”. A Debrett’s article of 2023: “knee length cocktail dresses are the most popular choice”. Canadian Heritage allows a “Dinner dress (long or short)”.
We follow the guide: long is the safe choice, because it is right under all three. The article reports what is popular, not a rule.
For men, Debrett’s wants a hand-tied bow tie. A long tie, the “Hollywood black tie”, “would look unsuitable” at most formal private black tie events in Britain.
Switzerland: the Protocol Regulations of 2026
In force since 15 June 2026, they set one dress rule for two ceremonies with ambassadors. The official texts are German, French and Italian; the English translation is “for information purposes only and has no legal force”.
| Ceremony | Dress |
|---|---|
| Presentation of credentials by a new ambassadorSection III.5 | Dark suit, national dress or uniform |
| New Year greetings of the diplomatic corpsSection VII.4 | The same |
| The Federal Council’s yearly event for the diplomatic corpsSection VIII.2 | “Dress code shall be determined by Protocol”: read the invitation. |
| Foreign military uniformsSections XV.1 and XV.3 | Forbidden in Switzerland. The Federal Department of Defence may allow one in some very specific cases. Accredited defence attachés may wear theirs on duty. |
The rule of section III.5 in its own words:
- German: “Für die Zeremonie ist dunkler Anzug, Nationaltracht oder Uniform vorgeschrieben.”
- French: “La tenue pour cette cérémonie est la tenue foncée, le costume national ou l’uniforme.”
- Italian: “La tenuta prescritta per questa cerimonia è l’abito scuro, il costume nazionale o l’uniforme.”
- English, for information only: “The dress code for this ceremony requires dark-coloured clothing, traditional attire of the given country or a uniform.”
Our reading, not the text
For men: a navy or charcoal suit, a white shirt and a tie. For women: a dark outfit at the same level; the text sets no separate rule. The French term is “tenue foncée”, not “tenue de ville”.
Our outfit helper opens set to an official event, dark suit. Menswear only, for now.
France and Italy
We found no dress rules published online by the French or Italian state protocol services. One official Italian text gives a hint: in 1991, the Diplomatic Ceremonial of the Republic called white tie (“marsina o frac”) “praticamente desueto” (practically disused) at official ceremonies in Italy, with the “smoking” ever more frequent.
On a budget
Our view, not an official rule
- One navy or charcoal suit covers the lounge suit, the Swiss dark suit, interviews and funerals.
- Hire white tie and morning dress for a single event. Hire black tie too, until you need it often.
Questions
What does “lounge suit” mean on an invitation?
A suit, a shirt with a turndown collar and a tie: the same as a dark suit or business suit.
What if the invitation has no dress code?
Wear a lounge suit (Canadian Heritage).
Can I wear black tie in the daytime?
No. Canadian Heritage: black tie is “never worn during the day”.
Can I wear national dress instead?
Yes. Canadian Heritage: “In all circumstances, national costumes can replace ceremonial wear.” The Swiss rule names national dress too.
Does black tie mean a black dress?
No. Debrett’s: “dresses need not be black”.
Related
Sources
- Swiss Federal Department of Foreign Affairs, Protocol RegulationsOverview page, published on 17 July 2026. The regulations in German, French and Italian (official) and English (for information only). Checked on 22 October 2026.
- Canadian Heritage, Dress for national ceremoniesPage modified on 3 December 2024. In French, modified on 11 October 2017. Checked on 22 October 2026.
- Debrett’s, Events and dress codesChecked on 22 October 2026.
- Debrett’s, Deconstructing dress codesArticle of 6 December 2023. Checked on 22 October 2026.
- Diplomatic Ceremonial of the Republic (Italy), Circular no. 7 of 31 May 1991On wearing decorations. Checked on 22 October 2026.