My husband and I married in 2003 and have two children. Since then, I have been filing my taxes as single and claiming one child, and my husband as head of household and claiming the other child. We're worried. What's the best way for us to file? How can we fix what we've done so far?

From 2003 onward your only options are to file as Marred Filing Jointly (MFJ) or married Filing Singly (MFS). You may not file as single or as Head of Household if you are married. There are some exceptions, having to do with couples who are still legally married but have separated and living apart - but those exceptions don't apply here. For the vast majority of married people it is best to file as MFJ - unless you have some unusual circumstance, such as one person having significant medical bills that could be deducted only if filing as MFS.

You can file as married filing jointly (MFJ) or married filing separately. In most cases, it is better to file as MFJ. If you file MFS, you will not get many credits and deductions.Read Your U.S. Tax Return: Filing Status for Married (http://taxipay.blogspot.com/2008/02/filing-status-for-married.html)

You and your husband should file Form 1040X to amend/correct your prior year tax returns that were incorrectly filed.