I am not that familiar with Series established under an LLC so I am wondering what type of identifying documentation is there? We have a CTR on a customer that has several Series businesses-each have their own EIN. We use the Secretary of State Certificate of Formation filing number for the identification on businesses but all I have found is for the primary LLC. Should there be anything filed with the state of Texas for the series? Each series has its own company agreement but those aren't filed. I am assuming we would have a separate Part I for each Series just not sure what to put on ID for each one.