To qualify for EITC, you and your spouse, if filing a joint return, must have a Social Security number or SSN issued by the Social Security Administration that is valid for employment and that is issued before the due date of the tax return including extensions.
Any qualifying child listed on the Schedule EIC must also have a SSN that is valid for employment and that is issued before the due date of the tax return including extensions. If the child was born and died during the year, you do not need a SSN.
You cannot use an ITIN, Individual Taxpayer Identification Number or ATIN, Adoption Taxpayer Identification Number, to claim EITC.
The Protecting Americans from Tax Hikes or PATH Act made several changes to the tax law, including preventing retroactive claims of the EITC by amending a return or filing an original return for any earlier year in which the individual or anyone listed on the return did not have a SSN valid for employment. You can't claim EITC unless the Social Security number for you, your spouse (if married filing a joint return) or a qualifying child is issued before the due date of the return including any valid extensions.
There is additional information for persons having social security cards saying “Not valid for employment” or “Valid for work with INS or DHS authorization” and other situations in Publication 596, Earned Income Credit or Publication 596 (SP) Credito por Ingreso del Trabajo.