This is what the IRS means by a "carryback adjustment".
" If you can't claim a credit for the full amount of qualified foreign income taxes you paid or accrued in the year, you're allowed a carryback and/or carryover of the unused foreign income tax."
Please see the Carryback and Carryover of Unused Credit section in: Topic No. 856 Foreign Tax Credit.
Also, in Topic No. 856 Foreign Tax Credit Please see the section labeled Computing the Credit When Filing Form 1116. "If you use Form 1116 to figure the credit, your foreign tax credit will be the smaller of the amount of foreign tax paid or accrued, or the amount of U.S. tax attributable to your foreign source income."
This may affect the amount of refund that you anticipate getting.
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