8879-C

IRS e-file Signature Authorization for Form 1120

Agency
IRS
Revision
2021
Fillable fields
16
Pages
2
Official source
IRS form page
Checked
October 21, 2026
Fill 8879-C online
Page 1 of form 8879-C

Form 8879-C (2021): IRS e-file Signature Authorization for Form 1120

Form 8879-C is the IRS e-file Signature Authorization for Form 1120. The form says a corporate officer and an electronic return originator (ERO) use it when the corporate officer wants to use a personal identification number (PIN) to electronically sign a corporation's electronic income tax return and, if applicable, consent to electronic funds withdrawal.

This is the 2021 edition, printed for calendar year 2021 or a tax year beginning in 2021. The ERO completes the top of the form and Part I, the officer reviews the return and signs Part II, and the ERO completes Part III. The form says "Do not send to the IRS. Keep for your records." The ERO keeps it.

The IRS About page for Form 8879-C lists Form 8879-CORP as the current revision, used for electronic signature authorizations for Form 1120, Form 1120-F or Form 1120-S. You can fill out this 2021 Form 8879-C free in your browser on this page and download it without an account.

What's on Form 8879-C

Heading: corporation and tax year

The tax year (calendar year 2021 or a tax year beginning in 2021), the name of the corporation and its employer identification number.

Part I: Tax Return Information

Five amounts in whole dollars from Form 1120: total income (line 11), taxable income (line 30), total tax (line 31), amount owed (line 35) and overpayment (line 36).

Part II: officer's declaration

The officer declares under penalties of perjury that the return is true, correct and complete, consents to its transmission and, if applicable, authorizes an electronic funds withdrawal.

Officer's PIN

Two boxes, check one only: authorize the named ERO firm to enter the officer's PIN, or the officer enters the PIN. The PIN may not be all zeros. Then the officer's signature, date and title.

Part III: Certification and Authentication

The ERO's six-digit EFIN followed by a five-digit self-selected PIN, the ERO's certification, and the ERO's signature and date.

How to fill out Form 8879-C

  1. 1

    ERO: top of the form and Part I

    Enter the corporation's name and EIN, then the Part I amounts from the corporation's 2021 income tax return. The form says zeros may be entered when appropriate.

  2. 2

    ERO: authorization line

    If the officer authorizes the ERO to enter the PIN, enter the ERO firm name on the Part II authorization line, not the name of the individual preparing the return.

  3. 3

    Officer: review and choose

    Verify the accuracy of the return, then check one box in Part II. When authorizing the ERO, indicate or verify the PIN, which the form says is five digits other than all zeros.

  4. 4

    Officer: sign and return

    Sign, date and enter a title in Part II, then return the form to the ERO. The form lists hand delivery, U.S. mail, private delivery service, email, Internet website and fax.

  5. 5

    ERO: Part III

    Enter the six-digit EFIN followed by the five-digit self-selected PIN, then sign and date. The form says the ERO enters the officer's PIN on the input screen only if authorized.

Why fill Form 8879-C on indox

You get the real form, filled in a browser tab, with nothing standing between you and the finished PDF.

  • Fill the form right in your browser, no software to install
  • Free to fill and free to download, with no account
  • The official blank straight from the IRS, not a copy someone retyped
  • Works on a phone, tablet or computer

Where it goes, record keeping and payments

Not sent to the IRS

The form says not to send Form 8879-C to the IRS unless requested to do so. The ERO retains the completed form.

Before transmission

The form says the corporation's return will not be transmitted to the IRS until the ERO receives the officer's signed Form 8879-C.

How long the ERO keeps it

For 3 years from the return due date or IRS received date, whichever is later. The form says it can be retained electronically under the recordkeeping guidelines in Rev. Proc. 97-22.

Copies for the officer

The ERO provides the officer with a copy of the signed form on request, and a corrected copy if changes are made to the return, for example after the officer's review.

Revoking a payment

The form says to contact the U.S. Treasury Financial Agent at 1-888-353-4537 no later than 2 business days prior to the payment (settlement) date.

Related forms

Who fills out Form 8879-C?

  • Corporate officers

    The form says the officer verifies the corporation's return, checks one box in Part II, indicates or verifies the PIN, signs, dates and enters a title, and returns the form to the ERO.

  • Electronic return originators

    The ERO enters the corporation's name and employer identification number, completes Part I, gives the form to the officer, and completes Part III with a signature and date.

  • Corporations filing the 2021 Form 1120

    The Part I amounts come from the corporation's 2021 Form 1120: total income, taxable income, total tax, amount owed and overpayment.

  • Officers who do not use a PIN

    The form says a corporate officer who does not use Form 8879-C uses Form 8453-C, U.S. Corporation Income Tax Declaration for an IRS e-file Return, instead.

  • Current revision: Form 8879-CORP

    The IRS About page lists Form 8879-CORP as the current revision for electronic signature authorizations for Form 1120, Form 1120-F or Form 1120-S.

Two people complete it: a corporate officer and the ERO that files the corporation's 2021 Form 1120 electronically. The ERO keeps the signed form, and the form says not to submit it to the IRS unless requested.

Official sources and the blank

Do it all with indox

View all 123 tools

Questions about Form 8879-C

Is Form 8879-C sent to the IRS?

No, unless the IRS requests it. The form says the ERO retains the completed Form 8879-C.

Who enters the officer's PIN?

Either the ERO, if the officer checks the box authorizing the named ERO firm, or the officer. The form says to check one box only.

What if the officer does not sign with a PIN?

The form says a corporate officer who does not use Form 8879-C uses Form 8453-C, U.S. Corporation Income Tax Declaration for an IRS e-file Return.

Is this the current version of the form?

This page hosts the 2021 Form 8879-C. The IRS About page for the form lists Form 8879-CORP as the current revision, used for Form 1120, Form 1120-F or Form 1120-S.

How can the officer get the form back to the ERO?

The form lists hand delivery, U.S. mail, private delivery service, email, Internet website and fax.

How long does the ERO keep Form 8879-C?

The form says 3 years from the return due date or IRS received date, whichever is later.