Do I have to wear a tie to an interview?

This depends on what the dress code of the company is, which you can find online or ask a recruiter/representative. If you cannot find the dress code is then you should make the assumption to look clean cut and professional, or look at the industry and see if there is a clear style (eg. If you are applying to be a lawyer then you should wear a suit - definitely not jeans and t-shirt). It is important to think of the impression that you will be giving and dress accordingly.

Maarten Karremans