It is a bit confusing:
See page 10 of the Ohio instructions under : Do Both Nonresident, Married Filing
Jointly Taxpayers Have To Sign the
Return?
Exception to the General Rule:
Your spouse does not have to sign a married
filing jointly return only if all three of the
following apply:
? Your spouse resided outside Ohio for the
entire year; AND
? Your spouse did not earn any income in
Ohio; AND
? Your spouse did not receive any income
in Ohio.
Given that the nonresident doesn't have to sign, the nonresident is not filing a joint return.
Looking further, I found IT 2006-04 Personal Income Tax: Nonresident Married Filing Jointly -- Issued September, 2006; Revised March 2007 which explains the rule more clearly. The resident taxpayer will complete his return as if he was filing jointly, then the OH resident can reduce the tax by the nonresident credit - this is the fraction of nonresident income divided by total income.
See the following links
Ohio IT 2006-04 Personal Income Tax: Nonresident Married Filing Jointly -- Issued September, 2006; Revised March 2007 - <a rel="nofollow" target="_blank" href="
https://www.tax.ohio.gov/ohio_individual/individual/information_releases/it200604.aspx">https://www....>
Ohio instructions: page 10 - <a rel="nofollow" target="_blank" href="
https://www.tax.ohio.gov/portals/0/forms/ohio_individual/individual/2016/PIT_IT1040_Booklet.pdf">htt...>
