by Valerie Bonk > University of Maryland, College Park

If you don’t have time for laundry or the weather’s unpredictable, finding what to wear to class can be challenging enough, let alone finding the right clothes for an internship or part-time job, where sometimes, literally, your future depends on it.

Depending on the industry, proper clothing can range from a suit and tie to jeans and a t-shirt. Knowing the dress code before your interview or the first day can make or break others’ impressions of you.

To be melodramatic: Save this article. Save your career.

Casual Dress

When it comes to “casual dress,” pretty much anything goes as long as it is appropriate for the task at hand. Radio stations, technology companies and dance studios, for example, all often call for casual attire—which doesn’t meant dress like you’re going to a tailgate. No bare midriffs, or inappropriately tight pants. Save the muffin-tops for the break room. Liza Frient, a preschool assistant, describes casual attire in her workplace as “jeans or khakis, a comfortable shirt and tennis shoes or something easy to run in.” Even if your position calls for casual dress, for your interview, you might want to play it safe by wearing business casual attire.

Business Casual

Office environments generally call for “business casual.” The term can be confusing: business suggests a suit and tie and casual suggests jeans. And no, you can’t get by wearing a jacket, tie and jeans. Business casual is a happy medium between the two names. It should be neat, clean and non-offensive. This means pants or a skirt in conservative colors, no flashy patterns, a shirt in a plain or subtle pattern and generic, comfortable shoes—NO sneakers. Jackie Hilliard, an Administrative Assistant at Lockheed Martin, an advanced technology company says that she “prefer[s] to be overdressed rather than underdressed.” Hilliard’s definition of business casual is, “slacks, a blouse and pumps.”

Business Professional

What about that scary “business dress” code? In a corporate, more formal headquarters location, business professional attire is the rule. Men should wear a suit and tie and women should wear skirts or suits with pants or skirts and hose. “It's always best to err on the side of more formal in the corporate environment,” says Melanie Winyall, an independent consultant. “You never know when you might be pulled into a meeting with upper management.”

No matter what the dress code is, make sure that you follow your workplace’s general interview and professional guidelines, says Bob Askew, Executive Vice President of CRAssociates, a healthcare service provider. “People should be nicely groomed, no long fingernails, no long beards, clean in appearance and no dreadlocks,” says Askew.

If you really don’t know the guidelines of your office before an interview or the first day, don’t be afraid to ask. You’re expected to be professional, not psychic, and your supervisor is more likely to be impressed by your initiative and responsibility than put off by your unfamiliarity with corporate fashion guidelines—which, after all, they probably detest as much as you do.