While it's possible you paid the taxes down that close, it's always good to double-check. You need to be sure you entered your income and withholding, tax payments, etc. correctly, and that there are no typo's, misplaced decimals or commas, etc.
Print out your return and go over each line carefully to be sure your entries are correct. Compare it to last year's return and see if you spot anything that looks different, and if so, investigate your entries for that topic. Also be sure you received any tax credits you were entitled to, such as the Earned Income Credit, if applicable.
