Example: Taxpayer H, a resident individual, has Connecticut adjusted gross income derived from or connected with sources within qualifying jurisdiction Z, and files an income tax return with that jurisdiction. Under the laws of jurisdiction Z, credit is allowed against the income tax imposed by that jurisdiction, to persons who are nonresidents of jurisdiction Z, for income tax payable to another jurisdiction on the same income that is subject to the income tax imposed by jurisdiction Z. If Taxpayer H, in filing his income tax return with jurisdiction Z, claims the credit allowed under the laws of that jurisdiction for income tax payable to Connecticut on the same income, Taxpayer H shall not be allowed a credit against Connecticut income tax for income tax paid to jurisdiction Z.
Conn. Agencies Regs. § 12-704(c)-1