The W-4 he gives to his employer only tells the employer how much tax to withhold from his paychecks. That form does not go to the IRS and does not dictate how you have to file your tax return. His tax withholding will be different. What is important is to file correctly using the correct filing status. You have both been making big mistakes by filing as single. Whether it has been to your advantage financially, whether you have "double dipped" by using the same itemized deductions, or whether you have kind of shot yourselves in the foot many times is impossible to know since we have no idea what kind of income you have had or if you have missed out on child-related credits, etc.
**Disclaimer: Every effort has been made to offer the most correct information possible. The poster disclaims any legal responsibility for the accuracy of the information that is contained in this post.**
