1) Tax return credit 
n. in taxation accounting, using a current tax year's deductions, business losses or credits to refigure and amend a previously filed tax return to reduce the tax liability.
(n) Carry back is the practice by which the loss incurred in a particular year is used to setoff the gain or profit of the previous years so as to reduce the tax burden of the previous years where there was a taxable profit.
A method for receiving a refund of back taxes by applying a deduction or credit from a current year to a prior year. (See also: carryover)