It's well past April 15. So, unless you applied for an extension, the stress and frustration of filing your federal tax return should be a distant memory by now. But what if you suddenly realize there's a mistake on your return or a new development that affects the amount of tax you should have paid? What do you do now? Whether the mistake or development is in your favor or the government's, filing an amended tax return is often the next step.

Filing an amended return isn't particularly difficult, but there are a few things you should know about the process before getting started. It also helps to be familiar with some of the more-common occurrences that can trigger the need for an amended return (in addition to just a mistake). That way, you'll know to check your previously filed return if and when they happen. Because every taxpayer should have a basic understanding of what it takes to change their return after it's filed, here are 10 tips on how and when to file an amended tax return.

Let the IRS Correct Certain Errors

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You don't need to file an amended return if you discover a simple math or clerical error on your return. The IRS can correct those types of mistakes on its own. An amended return isn't necessary if you forgot to attach a certain