There are two basic questions: Is what you are doing now working for you, and does it meet IRS rules? If the answer to both of these is yes, than I wouldn't recommend changing.
There are two ways to operate that pass IRS rules. One is to be a committee of the school. The money goes into a school account, and your group isn't a separate business entity (you don't have a separate tax ID number, for example). The second is to operate as an independent entity with 501c3 tax-exemption from the IRS.
Here's an article that explains the advantages of filing for 501c3 status in more detail: 501c3 for PTOs.
- Craig
Links in this post:
501c3 for PTOs: https:/classic.ptotoday.com//pto-today-articles/article/394-501c3-for-ptos