A spokeswoman for the Internal Revenue Service says that while the agency has clear guidelines on whether a taxpayer may file as single or married, there is often flexibility within those categories.

Karen Connelly with the IRS Denver office says for example a single person may also have the option of filing as a head of household if they paid more than half the costs of a household that includes at least one other person during the year. She says married people likewise have a choice between filing jointly or filing separately.

Connelly says you marital status is determined by whether or not you were married on the last day of 2012, with the qualifier that if you had spouse that died during the year you can still file a joint return. Connelly advises taxpayers to research what category works best for them and to act accordingly.