Many people are in circumstances that prevent them from having their documentation together so that they can file their tax returns by April 15. While it might be tempting to file an amended return later, it's actually a better idea to file a tax extension. You can file an extension electronically, and file your tax return on October 15 electronically; an amended return can only be filed on paper. This is an especially attractive option for those who still want some deductions and credits they can get for 2009, even though it's 2010. Also, filing a tax extension can be useful for those whose investment dividend statements are slow in coming, or who are waiting on K-1 forms for a business.

However, it is important to note that filing an extension does nothing for those who can't pay their taxes. Even though you haven't filed a tax return, you still have to pay your taxes, sending in the amount of money you think you will owe.