Can I file as Married on my W4 if I am not legally married? would this affect how I file my taxes?

[DianeW · Accepted solution]

You should use single, then add the number of exemptions you will claim on your tax return to create the correct amount of withholding for your situation.  The key is that you have enough tax paid in throughout the year so that you do not have too little withholding creating a large balance (tax) due at the end of the year.

For each exemption you claim on your W4, you will have less tax withheld from each pay check, or more take-home pay.   You are allowed to complete and submit a new W4 to your employer as many times as you want or need to throughout the year to adjust the withholding for the best accuracy.