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Step 1 of 15Internal Revenue Service · 1120 · 2025

IRS Form 1120 Online

Use this workflow to prepare Form 1120 for a domestic corporation, review the completed PDF, and mail the return or packet to the proper IRS address for the filing situation.

Current step
Filing period
Tax year begins, Tax year ends, and Tax year ending year
This step
3 fields · 3 required

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Step 1

Filing period

Enter the tax year printed at the top of Form 1120.

3 required

Need more context?

The form is ready to fill now. If you want supporting instructions, mailing notes, or source links, they are below.

What you need+
  • Corporation legal name, mailing address, and EIN
  • Tax year dates and incorporation details
  • Gross receipts, deductions, taxable income, tax, payments, and balance due or refund details
  • Applicable schedule details and supporting statements
  • Officer signature and preparer details when required
  • Signed form (wet signature required)
  • Supporting schedules and statements (optional) — Attach any schedules, statements, elections, or supporting pages that must accompany the corporation return.
  • Payment voucher or payment support (optional) — Attach payment documentation if you are mailing payment materials with the return.
How it works+
  1. Fill out the form
  2. Add attachments
  3. Preview the PDF
  4. Mail it
Where it gets mailed+

Enter the recipient address during checkout.

Packet order+
  • Cover sheet (auto-generated)
  • Completed form PDF
  • Attachments (in the order you upload)
Common mistakes+
  • Using a stale PDF instead of the current IRS revision.
  • Mailing the return to the wrong IRS address for the corporation's location or payment status.
  • Leaving required schedule lines or supporting statements out of the mailed packet.
  • Forgetting the officer signature or preparer information when the return requires it.
FAQs+
Does this workflow choose the IRS mailing address for Form 1120?

No. The workflow generates the completed PDF, but the filer should confirm the current IRS mailing address from the latest Form 1120 instructions before checkout.

Can attachments be included with the mailed return?

Yes. Add supporting schedules, statements, or payment documents as attachments so they are appended to the mailed packet.

Sources+
Related+
Last verified+

Last Internal Revenue Service verification: May 4, 2026