We always roll some money over, though $20,000 sounds like a lot unless you're saving for something major like playground equipment. Our PTO always pays for assemblies at the start of the new school year, and start up funds are needed for Back to School Night and our first fundraiser. I never heard about a rule regarding this, either.
I have been a member of pto's in our school district for 7 years and at the end of each year the money that was left after all of the expenses were paid for the year was given to the principal to use for the children of the school -I was told that this is what a tax exempt organization does - is this true? At a recent meeting we were voting on this and a first time parent objected and said at his previous school they carried a $20,000. balance in their checkbook. My thoughts are to spend the money on the children that raised it rather than keep a big balance in your checkbook!