STYLE GUIDE · DRESS CODES
Black tie optional, decoded.
Black tie optional means the hosts will be in black tie and you're welcome to join them. You can also choose the step below: an elegant midi dress or a dark suit. Here's how to pick.
Updated · By the Delve to Life editors · Editorial standards
THE QUICK ANSWER
- Dress route: a floor-length gown, or an elevated midi or cocktail dress in a rich fabric.
- Trouser route: a tuxedo, or a well-fitted dark suit with a tie and polished shoes.
- Daytime: go one step less formal than you would for an evening event.
- Skip: anything casual. "Optional" applies to the tuxedo, not to the formality.
Three safe outfits
| Level | Dress route | Trouser route |
|---|---|---|
| Full black tie | A floor-length evening gown | A tuxedo or dinner jacket with a bow tie |
| The middle | An elevated midi in satin, velvet or crepe, with evening shoes | A black or midnight suit, white shirt and dark tie |
| The step below | A polished cocktail dress or formal separates | A navy or charcoal suit and tie |
All three are correct. Choose by venue and time: an evening ballroom points to the top row, an afternoon garden to the bottom.
What the dress code means
The phrase is mostly American. It's searched about 14,800 times a month in the US, compared with a few hundred in the UK and Australia, where invitations usually say "black tie" or "lounge suits". The Knot suggests "floor-length evening gowns or elevated midi dresses" and "tuxedos, or elegant dark suits with upscale shoes". For early afternoon weddings, it advises going one step less formal.
Black tie optional vs black tie
| Black tie | Black tie optional | |
|---|---|---|
| Tuxedo | Expected | Welcome, not required |
| Dress length | Usually floor length | Floor length or an elevated midi |
| Dark suit | Not appropriate | Correct |
For the full ladder, see dress codes, decoded.
For a wedding
- Avoid white and ivory.
- A long dress makes dancing harder, so a midi can be the more practical choice.
- Bring a wrap or coat. Formal venues and evening gardens can be cold.
- If you don't own a tuxedo, a well-fitted dark suit is the right answer. You don't need to rent one.
Build it from what you own
- A dark dress plus one statement. Add evening earrings, a satin bag or velvet shoes. This is the Audrey Hepburn formula.
- Your best suit, elevated. Wear a white shirt, a dark silk tie and freshly polished shoes.
- Formal separates. A satin skirt with a fine knit, or wide trousers with a silky top.
Then check it against your weather in the outfit studio.
Sources: The Knot, wedding guest attire cheat sheet; Debrett's, dress codes. Search figures: DataForSEO via OpenSEO, October 2026. These are common conventions; the host's or family's wishes always come first.