The IRS will mail you a letter saying why. $1,200 could be one of the stimulus payments. A common adjustment is if you claimed the Recovery Rebate Credit on 1040 line 30 when you already got the Stimulus payments or got the second one after you filed or reported the wrong amounts. Do you have an amount on line 30? And you had to report the right amount in each box. If you put the total in 1 box it would give you the other amount again. The IRS knows they already sent it to you. Line 30 is only if you qualify more.