@TomD8
I think we are unclear on what the taxpayer actually filed since the taxpayer is asking about a "credit." Even if there is no PY form in these states, the IL return should only tax the income allotted to IL and the CA return should only tax the income allotted to CA. There won't be a credit for NR taxes paid to a different state. If IL is not releasing the calculated refund because they want proof of a change in residency, that's different from an out of state tax credit.
I agree that what IL should be asking for is proof of a change in the taxpayer's permanent residence, and its not clear to me that an employer could ever certify that (how does the employer know the taxpayer's intent to change residences?) There must be some other proof that IL will accept.
