Mr. Ashby

Guides Dress codes explained

Dress codes explained, from white tie to casual

Eight rungs, each drawn in a suit and in a dress, with what to wear and when you will meet it. Pin it, print it, and never again wonder what “smart casual” means.

By Mr. Ashby, butler, retired. Updated 30 September 2026.

The short answer

From most formal to least: white tie, black tie, black tie optional, cocktail (also called semi-formal), garden party, business casual, smart casual and casual. When the invitation is vague, find the nearest rung and go one notch up.

Most formal at the top. Either column may be worn by anyone; the drawings simply show a suit and a dress for each rung. Nobody was ever sent home for looking as though they made an effort.

A dress code is not a riddle. It is your host telling you, in two words, what everyone else will be wearing. Find it on the ladder below, then check the clock and the place: after six in the evening, lean darker; a daytime event outdoors runs lighter.

Ink and watercolour sketch of white tie attire, a suit on the left and a dress on the right

Rung 1 of 8

White tie

Suit
Black tailcoat, trousers with a satin stripe, white piqué wing-collar shirt, white waistcoat, white bow tie, patent shoes.
Dress
Floor-length formal gown. Long gloves if you like.
When
State dinners and the grandest balls. Rare on both sides of the Atlantic, and the invitation will say so plainly.
Ink and watercolour sketch of black tie attire, a suit on the left and a dress on the right

Rung 2 of 8

Black tie

Suit
Black dinner jacket (a tuxedo), formal white shirt, black bow tie, patent or highly polished shoes. A white jacket in summer.
Dress
Floor-length gown or a very dressy cocktail dress.
When
Galas, evening weddings, formal dinners. In Britain it’s called a dinner suit. See black tie vs black tie optional.
Ink and watercolour sketch of black tie optional attire, a suit on the left and a dress on the right

Rung 3 of 8

Black tie optional

Suit
A tuxedo if you own one; otherwise a dark suit, white shirt and a conservative tie.
Dress
Gown, cocktail dress or elegant dressy separates.
When
Evening weddings and benefits. Mostly an American code.
Ink and watercolour sketch of cocktail attire, a suit on the left and a dress on the right

Rung 4 of 8

Cocktail

Suit
A dark suit, dress shirt and tie, leather shoes. Britain calls this a lounge suit.
Dress
A knee-length or midi cocktail dress, or dressy separates.
When
Most weddings and evening parties. “Semi-formal” means the same. “Festive” is cocktail with permission: a velvet blazer, a holiday tie, a little sparkle, and still no jeans.
Ink and watercolour sketch of garden party attire, a suit on the left and a dress on the right

Rung 5 of 8

Garden party

Suit
A light suit, or a blazer with chinos and loafers.
Dress
A midi or maxi day dress in florals or pastels, block heels or flats. Lawns eat stilettos; I once retrieved a shoe with a trowel.
When
Daytime outdoor weddings and parties.
Ink and watercolour sketch of business casual attire, a suit on the left and a dress on the right

Rung 6 of 8

Business casual

Suit
Trousers or khakis, a button-down or polo, blazer optional, loafers.
Dress
Trousers or a skirt with a blouse or sweater, or a simple dress.
When
Offices and work dinners. No jeans unless you’re told. A blazer rescues almost anything.
Ink and watercolour sketch of smart casual attire, a suit on the left and a dress on the right

Rung 7 of 8

Smart casual

Suit
Dark jeans or trousers, a collared shirt, a blazer if in doubt.
Dress
A dress, or nice jeans with a dressy top.
When
Good restaurants, date nights, networking. In Britain, traditionally no trainers and no T-shirts.
Ink and watercolour sketch of casual attire, a suit on the left and a dress on the right

Rung 8 of 8

Casual

Suit
Clean jeans or khakis, a plain tee or casual shirt, clean trainers.
Dress
A sundress, or jeans with a casual top.
When
Barbecues and daytime gatherings. Clean is the whole code.

If you are still not sure

Ask the host when you reply. If the answer is vague, choose the dressier of your two options, because overdressed is easily repaired: jacket off, tie in a pocket, and you are a rung lower in ten seconds. Underdressed cannot be mended in the hall.

In forty years I never once heard a guest apologise for being too smart. I heard a great many apologise for the opposite, usually to me, as though I might produce a tie from my waistcoat pocket. Occasionally I could. We kept three in a drawer by the door.

Say“Thank you, we’d love to come. How dressed up is everyone going?”

Questions

What is the difference between cocktail and semi-formal?

For practical purposes there is none. Both mean a dark suit and tie, or a knee-length or midi cocktail dress. After six in the evening, lean darker.

What is the difference between business casual and smart casual?

Business casual is office clothes without the suit, and no jeans unless you are told. Smart casual is a notch easier and is the one that allows dark jeans, with a collared shirt or a dressy top.

What does festive attire mean?

Cocktail attire with a seasonal touch: a velvet blazer, a holiday tie, a dress in deep green or with a little sparkle. It still means no jeans and no trainers.

What should I wear if the invitation has no dress code?

Ask the host when you reply; it is a perfectly ordinary question. Otherwise read the time and the place, lean darker after six in the evening, and dress one notch up.