Remember to file a new W-4 after you get married in order to not overwithhold or underwithhold taxes from your paycheck.
Two single taxpayers who both work and have children and are eligible for the earned income credit may be penalized by marrying. The earned income credit may be reduced or eliminated when you combine both of their incomes.
Same Sex Marriages: Same sex marriages are not recognized for federal tax purposes. A same sex couple can't file a joint federal return. If you live in a state that recognizes same sex marriages, you might be able to file your state return using a different filing status than your federal return.
Common Law Marriage: If you are living together in a common law marriage that is recognized in the state where you now live or in the state where the common law marriage began and the marriage is recognized under federal law, then you are considered married for federal tax purposes and can file a joint return.
Newly Married: If you were married during the current tax year, you are considered married for the entire tax year. For example, if you are married on December 5th, you are considered married for the entire year. You would file either a married filing jointly return or a married filing separate return.