Hi Eric,
That’s a great question. I had visited a business school information session last year which was also attended by one of the South Asian representative from GMAC. A very similar question was asked to the representative. He clearly said that ‘A student does not need to have a bachelor’s degree to give his GMAT exam. As per GMAT eligibility criteria, the lower limit set by GMAC is 18 years. Aspirants between the ages of 13 and 17 are allowed to appear for the exam on producing a written consent by their parent or legal guardian’.
He clearly emphasised that the minimum age to give GMAT is just 13 years. Hence a bachelor’s degree is certainly not a prerequisite to give the test.
Further I believe Business schools that use GMAT to select students for their courses have their own eligibility criteria which may include work experience and the previous degree along with a GMAT score range. However if you have spoken to the admissions representative from your choice of schools and they are alright with your situation then you should be fine.
Hope this helps. All the best.