I just updated my article on “Getting an EIN from the IRS” (on my Articles page) because my original article neglected to mention that your organization needs a new EIN after you incorporate as a nonprofit corporation in your state.
Here’s what I added:
If your group became a nonprofit corporation in your state, then you need a new EIN from the IRS in the name of the new corporation. A corporation is a new legal entity and you need a new EIN to match it. Use the same name as you used when incorporating. Look on the certificate you received from your state for your official legal name.
Read the full, updated article here: Getting and EIN from the IRS
If you have questions about applying for an EIN or the Form SS-4, read the chapter on “Checking Accounts Done Right” in my book Money Management in a Homeschool Organization