An amended return to claim a refund generally can be filed up to three years from the due date of that return (or the actual filing date if after the due date).
A fixed deduction allowed to every taxpayer, except those who may be claimed as a dependent by another person. Extra exemption deductions are allowed for a spouse on a joint return and for each qualifying dependent. A deduction of $3,400 is allowed for each exemption claimed on 2007 returns, but the deduction is phased out for certain high income individuals.