Bylaws-wise, your principal is 100% wrong. Check your current PTA bylaws. They'll likely have the official process listed for disbanding your PTA. Typically, that's something like: 1) announce that you're considering the change and give members a 30-day advance notice of the meeting where you'll be considering it; 2) at that meeting (provided a quorom is present, and your quorum number should also be in your bylaws), usually a 66.6% or 75% (at most) vote of the members in attendance is required to disband the PTA.
Getting 100% of any group to agree on anything is virtually ungeard of.
I would ask the principal what the concern is. He or she may think this is a huge decision (not realizing that the switch is typically a virtual non-event for most of your parents; they won't feel any difference) and therefore warrants extra attention. I think that's fair. Sp in that case, i think communicating beyond just your PTA membership could be a good idea.
But still, then requiring 100% approval is unheard of. First of all, getting 750 people even to respond is virtually impossible (that's why quorum rules are used); and secondly, getting 100% agreement on anything is even more impossible (more impossible?).
Anyway... let us know how we can help. Would be interested to know more about your principal's concerns.
Maybe your principal just feels that every parent should be able to have a voice in a big decision like this. I can't fathom that he/she would actually expect all 750 parents to agree one way or the other. I would say that you put out an announcement to all of the parents that there will be an informational meeting to discuss this possibility. Then during that meeting present the pros and cons of each organization and express the board's opinion of which option is the best fit for how your group operates. Then set a meeting date for a vote. Send home an announcement to all parents about the vote and whatever the majority of voting parents decides is how your group organizes itself for next year.
I guess I feel that all parents should be made aware of what is going on with the group and then let them decide whether they want to be a part of that decision or not. Some parents aren't really going to care one way or the other.
We are exploring (and leaning heavily towards) switching from a PTA to a PTO. Our principal announced we would need ALL parents of the 750 students in agreement in order to change over to a PTO.
I sense this is inaccurate, but don't know the rule.
What percentages are needed to make this switch?