We collectively just did this earlier today with Iowa and Arizona. There are no hard and fast rules, but intent seems to be the key. Intent is indicted by things like registering a car, getting a driver's license, voting, paying utility bills, etc.
Let me give OH a shot (or rather let me give google a shot at OH):
(I) “Resident” means any of the following, provided that division (I)(3) of this section applies only to taxable years of a trust beginning in 2002 or thereafter:
(1) An individual who is domiciled in this state, subject to section 5747.24 of the Revised Code;
(J) “Nonresident” means an individual or estate that is not a resident. An individual who is a resident for only part of a taxable year is a nonresident for the remainder of that taxable year.
Now if we only knew what domiciled means, but we are told where to look: section 5747.24 Presumption of domicilehttp://codes.ohio.gov/orc/5747.24
You can read it, but it basically presumes you are a resident of Ohio unless you can meet a five part test. This is the anti-snowbird test to make people spending the winter in Florida residents of Ohio for tax purposes.
http://www.tax.ohio.gov/ohio_individual ... tatus.aspx
If you are unsure of your state of residency, Ohio law provides that you will be considered a full-year nonresident of Ohio only if you meet all five of the following requirements:
During the entire taxable year you had at least one abode outside of Ohio,
You spent no more than 182 contact periods in Ohio during the taxable year,
You were not a part-year resident of Ohio during the taxable year,
By May 31 of the immediately succeeding calendar year you file, as appropriate, either the affidavit or notice of non-Ohio domicile or notice of no Ohio income tax liability (below),
These documents do NOT contain any false statements.