Finishing business school is a daunting prospect and not just for the reason of having to put all of your postgraduate learning into practice. Come interview season, another persistent worry that many MBAs will have is the all-important question of what to wear.Terms ‘business dress code’, ‘business casual’ and ‘business style’ are frequently utilized as guidelines on how to dress appropriately in the business world. But, how important is it to know about them? Do the rules really apply to you if you’re heading into a job at a tech start-up for instance? What is ‘business casual?’If Vanity Fair’s opinion is anything to go by for business fashion advice, then it seems that men can’t go far wrong with a blue suit, a blue tie and a white shirt – á la David Cameron and Barack Obama – if you’re planning on doing a spot of world leadership. For women, the impression of what to wear is perhaps a bit more confusing, what with the examples of Laura Chinchilla, the President of Costa Rica, in a flowing red dress and scarf, and Joyce Banda, the president of Malawi, pictured in brightly coloured traditional African dress. Surely no one – male or female – would have this amount of courage in their first year out of business school?The question is then, where is the line between being too ‘out there’ and lacking any personality at all? Many of the sites that offer advice on business style err on the side of the conservative because the guidance is there to cover the extremes. But not all business graduates will need to, or want to, come within six foot of a pair of cufflinks. Not to mention a pocket square.The joys of business casual and casual casualMark Zuckerberg, CEO of Facebook and billionaire in his 20s, is one of the most envied businessmen in the world. Partly, one might hazard, because of his freedom to dress however he wants and still be taken seriously. If however, Zuckerberg had walked into a business job interview having not owned one of the most important social media companies of the internet revolution, it’s doubtful he would be taken all that seriously.A professional business dress code is important if you’re still trying to make a name for yourself. You may have been the case study champion in your strategy workshop wearing only a basketball vest but that does not mean the business world is prepared for this.If you’re looking to compromise for the sake of your career then it’s business casual attire for you, or ‘Biz-Caj’ as some may like to call it. This is a step down from a suit and tie but a step up from ripped jeans and a t-shirt. The main thing is to look clean and presentable. As these handy stock photos can illustrate. This relaxed look is the usual for many businesses but make sure you know your new company\u0027s dress code before turning up like this on your first day. You\u0027ll be given a chance to suss out their dress code in your interview and to act accordingly thereafter. Initially however, for your interview, the smarter the better.Following the business dress code: having professional business styleProfessor of psychology at the University of Hertfordshire and fashion psychologist, Dr. Karen Pine told Forbes that sometimes business casual is not always the best option for business.She says: “When we put on an item of clothing it is common for the wearer to adopt the characteristics associated with that garment. A lot of clothing has symbolic meaning for us, whether it’s ‘professional work attire’ or ‘relaxing weekend wear’, so when we put it on we prime the brain to behave in ways consistent with that meaning...It’s the reason why we feel fitter in our sports clothes, or more professional in work wear.”This is good guidance if you’re one of those people who has trouble keeping to a work routine or even those who find it difficult to distinguish between work and home life. If you dress casually every day of the week how are you supposed to metaphorically throw off the business week and relax into the weekend. Likewise, how do you prepare yourself for business if you’re wearing what you wore to the pub on Saturday (minus the beer stains). Some will find distinguishing business from pleasure pretty easy without the need for wardrobe divisions, but others might not.Respect for the underdressed – casual business without business casualRecent studies at Harvard Business School have found that there may be something in an unconventional business dress code. In research conducted by faculty members Francesca Gino, Anat Keinan, and doctoral student Silvia Bellezza, entitled “The Red Sneakers Effect: Inferring Status and Competence from Signals of Nonconformity” it was found that wearing clothing out of the norm, for example to conduct a lecture or head a board meeting, could in fact earn you more respect and a higher status in the eyes of your colleagues or students.The findings are not without their obvious potholes however and the researchers realize this. While you may want to make an impression about your unconventional business style straight away, perhaps your big job interview with a private investment company is not the time to turn up in your usual get up of a hooded jumper and shorts. The interviewers might admire your courageousness…but they may also assume you’re not serious about the job.The time to start experimenting with your business style is when you have your generic polished black loafer firmly in the door. Only then can you replace it with whatever shoe/boot/heel/flip flop you like. Once your bosses and your colleagues are aware of your competence and your way of working, dressing slightly quirkier and more (business) casual should not have any effect on how people see you as a businessperson.