I suppose you are asking in regards to your data feeds which have higher fees for pros. I would say that if you trade as a member of an entity (like a limited partner in LLC) or as an entity yourself, then you are a pro at all times (even if you also trade your own account). If you are only trading in your own account as a retail trader, then you are not a pro. Passing a license would not automatically make you a pro.
That pretty much sums it up ler. Also if you're registered as a CTA you are considered a pro. For the exact definition, look at the exchange agreement that you have to sign when you apply for data services. The pro designation that you are talking about doesn't refer to how much you trade or whether or not you trade for a living, but rather your professional affiliation with firms in the industry or certain licenses that you hold.