If you live with someone but have never tied the knot, you both have to file your taxes as single. If you do decide to get hitched, your filing status changes.
If you are married you can't file as single, but you can file either jointly or as married filing separately.
If Married, Can I Claim Single?
As far as the IRS is concerned, there is no such status as married filing single. However, that doesn’t mean you must file jointly with your spouse. You can file your taxes as married filing separately. There are few benefits of married filing separately, and the overwhelming majority of married couples do not file separately. However, if your spouse owes legally enforceable past due debt such as child support, the married filing separately option makes more sense. When you file as married filing separately, you are responsible only for your own taxes. One caveat: If you live in one of the nine community property states, what is yours and what is your spouse's can become quite complicated. You may want to contact an accountant if yours is a community property state. In any case, you should run the tax numbers for both married filing jointly and separately to see which benefits you the most.
Separation and Divorce
Once you are legally divorced, you can file as single or as head of household if you have a dependent. However, if your divorce isn’t final as of December 31, or if you don’t have a separation maintenance agreement in force as of that last day of the year, you must file as married.
Married Filing Separately 2018
The Tax Cuts and Jobs Act, signed into law by President Donald J. Trump on December 22, 2017, goes into effect for the 2018 tax year. This doesn’t change the status for married filing separately a great deal from previous years, but if two spouses file separately, they must both either itemize or both claim the standard deduction. For 2018, the standard deduction has increased to $24,000 for a married couple filing jointly, which means far fewer people will itemize deductions. If you file separately, your standard deduction is $12,000 each. The TCJA limited the deduction for state and local property taxes to $10,000, so if you and your spouse both itemize, you can only claim $5,000 each. As noted, there are few benefits of married filing separately, and there are many deductions to lose. These include student loan interest and other educational credits, the child care and dependent credit and earned income credit. Other deductions are reduced for those filing separately rather than filing jointly. The TCJA eliminates all personal exemptions.
Married Filing Separately 2017
For 2017, the standard deduction is just $6,500 for someone married and filing separately. However, there is no limit on the state and local tax deductions, so if you live in a high tax state, each spouse can deduct half of the state and local property taxes.