If there's one thing a business school applicant fears, it's the GMAT, says Amy McLellan

There are a number of hurdles standing between the would-be MBA student and the business school of their choice. Perhaps the most formidable is the Graduate Management Admissions Test (GMAT), the official exam used by many business schools to assess the academic potential of candidates from institutions from around the world.

"A nightmare" is how Claire Pullinger, a former pharmaceuticals executive now studying at Said Business School in Oxford, describes her GMAT experience. Like many others, Pullinger booked some classes to get her number skills into shape.

"People have mixed views of doing these classes but I found it very helpful," says Claire. "If you're not that strong on the quantitative side then these classes do help because there's definitely a method to getting a good score."

And a good GMAT score does count. It is not the only measure used to select candidates but it does help business schools weigh an individual's ability to cope with the rigours of the MBA programme. The maximum score is 800 and two-thirds of test takers score between 400 and 600. The top business schools expect much higher: the average score on the INSEAD campus, for example, is 702.

It pays to prepare: past papers can be downloaded from www.gmat.com and organisations such as Kaplan in London run coaching sessions.

Genevieve Slonim from the admissions department at IESE in Barcelona advises taking six months to prepare for the GMAT. "The test has become so competitive because there are so many resources out there about how to prepare," she says. "The scores continue to get higher."

Some business schools use test scores to award bursaries and scholarships to high-flyers, and employers may ask for the GMAT score when interviewing someone for their first post-MBA post.

The test may be daunting but the first, and perhaps most important, step in the application process is selecting the right business school. This takes time and effort. Aim to match your checklist of skills and professional goals with the requirements and aims of the business schools. If in doubt, contact the school for an informal chat.

As a general guide it's worth spending 12 months preparing for your MBA year. This gives you time to research thoroughly the different schools, prepare for the GMAT, fill in all the application forms, get the necessary letters of recommendation and arrange your finances.

Claire Pullinger admits she left it all too late, which made for a stressful run-up to her year at Said. "It's all very time consuming - you have to do your GMAT, write essays, fill in application forms and do your full-time job."

Draw up a shortlist of schools and aim to visit your top three. Ask to sit in on classes, talk to current students and ask to be put in touch with alumni to gauge the return on investment.

Applying to business school can be time-consuming and expensive (most charge an application fee of around £100-£150, and it's recommended you apply to two or three). Along with the application form, you will have to submit a number of essays, showcasing different aspects of your career and your professional goals.

The next step is the interview, which for many business schools is the most important stage, particularly now that applicants can hire consultants to package their applications and vet their essays.

"The interview is not a formality," says Chris Jeffrey of Cass Business School in London. "The report we write up and present to the admissions committee is the key decider."

Professor Roy Westbrook, director of MBA programme at Said, explains: "It's about getting to know the individual and can be a pretty frank exchange. We like to get a feel for how demanding their work is, what they find particularly challenging, are they a soloist or a team-player and what is the strength of their motivation for doing the MBA."

Top tips for your application

Do your homework

Ask friends, colleagues and headhunters for their MBA opinions, attend MBA Fairs, scour the business school rankings, trawl the web, speak to alumni.

Give yourself time

You need at least six to 12 months to do your research, prepare for GMAT, write essays, arrange letters of recommendation and organise your finances

Practice means points

GMAT is tough. Know what to expect, do practice exercises and sign up for classes if you're weak in one area.

Attention to detail

Keep essays focused, personal and within the word count. Make sure you include everything the business school asks for.

Be yourself

Be honest about any academic hiccups or gaps in your CV. Explain your motivation and why this business school is the right one for you. And think about what your strengths are: what will you add to the classroom?

'The interviews were very open'

Axelle Poullier is studying for an MBA at Ashridge

Because I had worked in hotels for 11 years and didn't have the classic MBA background in finance or marketing, I wanted to find a business school that would be interested in my profile and give me feedback before I made a formal application. I went to an MBA fair in London and met the people from Ashridge, who were really helpful. In the end I applied to two business schools but Ashridge was my first choice.

It took about six months to go through the application process - you can do it quite quickly if you know exactly what you want. I prepared for the Graduate Management Admissions Test (GMAT) over the summer while I was working, which was difficult. Maths was never my best friend at school so I focused on that and did some intensive classes at the weekends. I also gave myself a month to practice all the exercises.

The application form was quite straightforward and I had to do an essay on leadership. The interviews were very open and pleasant. They are trying to identify your needs as an individual.