Fillable Form 8879‑C (Corporation) – Sign Online Instantly

Form 8879‑C, also known as the IRS e‑file Signature Authorization for corporate tax returns, allows a corporation to authorize the electronic filing of Form 1120, 1120‑S, or 1120‑F. Using our fillable PDF, you can complete, sign, and save the form without any extra software.

What Is Form 8879‑C?

This form serves as the electronic signature authorization for a corporation’s income tax return. It confirms that the corporation’s responsible officer has reviewed the return and consents to e‑filing.

How to Fill Out Form 8879‑C with Formize

Instead of downloading the PDF and opening a separate editor, simply click the "Fill out this form" button below. The Formize PDF Filler app will load directly in your browser, letting you type, select dates, and add an electronic signature.

Common Mistakes to Avoid

• Leaving the Signature field blank – the form is invalid without a signature.
• Entering an incorrect Employer Identification Number (EIN).
• Using an outdated tax year on the form.
• Forgetting to attach the signed form to the corresponding Form 1120 series.

Where to Submit Your Signed Form

After you finish, download the completed PDF and attach it to your e‑file submission through your tax software or send it to your tax preparer. The IRS does not accept paper copies of Form 8879‑C for electronic filings.

Need More Help?

Review the IRS instructions on the back of the form or consult a qualified tax professional. The Formize platform provides a smooth, secure environment for completing IRS forms online.