Amended Return
  
Embrace the pain of taxes. Be right. Be accurate. Disclose everything. But should something have been, um, omitted...., there is still an option: just file an amended return.
Like when you're telling your significant other about your trip to Las Vegas, and suddenly arms cross and eyes harden. You realize your story isn't going well. At that point, the reality TV shows have the main characters go ahead and file an amended story.
Basically, if you filed a tax return with the IRS (or with state authorities) and notice later that some error crept in, the way to correct the error involves filing an amended return. This lets the tax people know the new information. You'll still have to pay any difference in the amount of tax you owe. But it's better than letting the tax people find it on their own. That tends to make them very, very mad. Like when your significant other learns about your trip to Vegas from someone else.