Team 2228 used the school finance department for our first two years. This was the worst source of problems in operating the team. The school cut POs on Wednesdays only

which was a killer during build season. Bills submitted for payment well in advance of due date were still late. One mentor fronted the cost of materials and it took 1 year for the school district to reimburse the legitimate expense. All our funds were team raised, no taxpayer dollars from the school making the reimbursement delay even more difficult to accept. The school district was great on support in all areas other than finance. Their financial system response times and our short build season needs just did not fit.
This past year we looked into creating our own 501c3 and were about to do so until we found a pre-existing 501c3 in our school district who wanted to partner with us on the financial side. They get community service in the educational area as they wished. The team gets an independent checking account and credit card so that we now can control our timely ability to purchase materials and pay our bills. We still operate within the school district on all other matters which is great for concerns such as insurance.
This approach saved us the legal fees associated with forming a 501c3. It also saves us the yearly cost of director's insurance or having directors of the team 501c3 uninsured which would have been a concern.
Bottom line, school is happy and thrilled with the new model, 501c3 organization is happy, and our first year running finances this way was a great success.
