According to the IRS it is projected that almost 5 million taxpayers will amend their returns by filing Form 1040X during 2014. Many of those that file amended returns will do so to claim a refund or credit.
Taxpayers who need to amend their returns should file this form only after filing the original return. Generally, for a credit or refund, taxpayers must file Form 1040X within 3 years, including extensions, after the date they filed their original return or within 2 years after the date they paid the tax, whichever is later.
For example same-sex couples may want to consider filing amended returns as a same sex couple (legally married in a state or foreign country that recognizes their marriage) is now considered married for tax purposes.
For returns originally filed before Sept. 16, 2013, legally married same sex couples have the option of filing amended return to change their filing status to married filing separately or married filing jointly.
As always seeking the advice of a qualified tax professional to determine your best options is the best way to go.