I urge you to go ahead and register it only takes a few moments. There is a gal who visits this board from Texas and I recall her addressing this issue on the PTA discussion boards. If she does not respond here in a day or two I will email her for you.
This may be different in different states, but I am writing from Texas. We are a PTO, and were talking about becoming a PTA because of various reasons, one because of the tax exempt status. I know that there are a number of reasons to become 501(c)(3) and I know that PTOs can become tax exempt (with a fee), but I recently found out that all organizations get 2 sales tax free days. I thought that it was for 501(c)(3) only, but it's not. Any organization that fundraises on an occasional basis, can do this. Is there anyone from Texas out there, and did you know that?? We are so excited about it.