The last day to ask the IRS for a refund from the year 2004 is April 15, 2008. So if you need to file your '04 taxes, or forgot a deduction or tax credit, you'll need to get your returns postmarked by that deadline. In fact, the IRS estimates that some $1.2 billion in refunds is sitting in the Treasury waiting for people to file their 2004 returns.

Taxpayers have three years from the original filing deadline to request a refund of their income tax.

More information:

• How to file your back taxes
• Tips for filing your 2004 taxes
• Archived tax forms and instructions for 2004