What document is used for authorizing an ERO to e-file a return?

The correct document used for authorizing an Electronic Return Originator (ERO) to e-file a return is Form 8879, also known as the IRS e-file Signature Authorization. This form serves as a signature equivalent, allowing the taxpayer to authorize the ERO to submit their tax return electronically on their behalf.

Form 8879 incorporates essential elements such as the taxpayer's identification information and declarations that ensure the authenticity and accuracy of the return being filed. The taxpayer must sign this form, providing a clear and necessary consent for the ERO to proceed with the e-filing process.

The other options, while relevant in the context of tax filings, do not specifically serve as an authorization for e-filing. Form 8453, for instance, is used for transmitting paper documents that are associated with an e-filed return but does not function as the authorization itself. Forms 1040 and W-2 are tax return forms and income reporting documents, respectively, and do not have any role in granting an ERO the authority to file electronically. Thus, Form 8879 is the appropriate choice for this authorization purpose.