Whenever we go somewhere, let's say, to attend a party or a seminar, we check their dress code. This dress code might be written on the invitation card, or you can simply search for it online.
In the same manner, when you are appointed for an interview you have to follow a mandatory formal dress code. And when we say a formal dress code, we instantly think about wearing suits for men. Not only men but women should also wear a nice decent suit.
In most cases, formal pants and a blouse would do the work. However, it is always good to wear a formal coat and blouse to compliment a formal look. Other times business interviews would ask you to follow a casual dress code.
This means that you can wear anything that is not too fancy or too basic. Not the jeans and trainers kind of casual dressing but decent yet stylish trousers paired with a shirt.