We’ve all seen them: those shirts with the little buttons on the collar. But you might not have known that this type of shirt has a specific name. And it’s a name that is pretty similar to what most people call regular shirts.
The phrases button-up and button-down shirts are two of the most confusing in menswear. But the good news is that there’s a simple explanation about the difference between each one.
Button Up vs. Button Down Shirt: What’s the Difference?

The difference between button up and button down shirts is simple: button up shirts are these with buttons all the way up the front of the shirt. Button-down shirts are those with buttons on the collar that keep the collar down.
What is a Button Up Shirt?

Button up refers to the buttons on the front of a shirt. What this means is basically every shirt is a button-up shirt. Dress shirts, flannel shirts, and Cuban collar shirts are all button-up as long as they have buttons all the way up the front.
It doesn’t matter if they are long or short sleeved, casual or formal, or worn with a suit or jeans, buttons up the front mean the shirt is a button up. Types of shirts that aren’t button ups are those with zips, or with buttons that only go half way down the front.
What is a Button Down Shirt?
A button down shirt is a specific type of shirt with small buttons that attach the collar to the shirt. This keeps the collar in place while you’re moving around. The story goes that the type of shirt was invented for polo players who were annoyed at the collars flapping around as they played.
You’ve probably seem this type of shirt and know what we are talking about. If you don’t here is an image to clear things up. The image below also highlights an interesting point. Yes, a shirt can be both button up and button down. If fact, this is almost always the case.
Which is More Formal Button Up or Button Down?
There are both formal and informal versions of both these shirts. For the sake of this question, lets assume we’re talking about the most formal version of each shirt. In this case, a button up dress shirt is more formal than a button shirt.
If you’re going to a wedding or a black-tie event, you’ll likely choose a button-up dress shirt. But, button down shirts can be ok in many formal situations. You can wear one to an office with a formal dress code and I doubt anyone would bat an eyelid.
Is it Ok to Wear a Button Down Shirt Unbuttoned?

There’s a lot of debate around this, and ultimately it depends on the look you’re going for. If you’re wearing the shirt in a relaxed setting then go ahead and unbutton the collar, just make sure you open the top button while you’re doing it like in the image above.
You’ll look notably more casual than you would if the shirt was done up, but as long as you own it, you’re probably ok.
In more formal situation, I don’t think there’s much reason to unbutton the collar as the shirt is made to be worn with it buttoned down. It will have a better shape and ultimately look smarter with the collar buttoned down.
I should also mention that while you should undo the top button when you undo the collar buttons, the same rule doesn’t apply in the other direction—you can wear the top button undone with the collar buttons fastened.