Q. Do I file with all of them, just one or none?
A. None
You normally only have to file a return in the city you live in. It is not necessary to file one in the city(s) you work in, if different. Your employer will remit withholding to the city you work in, but you do not file a return unless you're claiming a refund or your employer didn't withhold enough (both highly unusual).
Many Delaware County school districts do have a School District Income Tax (SDIT).
To find out if you live in a school district (and/or verify that you don't live in a city) with an income tax, enter your address at:
http://www.tax.ohio.gov/Individual/LocalTaxInformation.aspx
