Form 1120 Item C: Date Incorporated — Optional but Match Form 5472 Item 1m

Item C: Date Incorporated — Technically Optional, Practically Advisable

Form 1120's Item C asks for the date of incorporation. If you follow the IRS Form 5472 instructions to the letter, they specify only the basic information in items B and E need to be completed for a pro forma 1120 filing — Item C (date incorporated) isn't strictly required.

But in practice, most tax practitioners fill it in anyway. The IRS rarely penalizes filers for providing more (correct) information, and filling Item C makes the form consistent with Form 5472.

Why Consistency With Form 5472 Matters

Form 5472 Item 1m asks for the same date of incorporation. If you leave Item C blank on Form 1120 but fill it on Form 5472, the two forms have inconsistent data. An IRS reviewer cross-referencing both forms sees a discrepancy and may flag it.

Filling Item C on Form 1120 with the exact same date that goes in Form 5472 Item 1m eliminates this inconsistency. The few seconds of typing are worth the smoother processing.

What Date to Use

Use the official date of incorporation from your state's certificate of formation. For most U.S. LLCs, this is on the Articles of Organization or Certificate of Formation issued by the Secretary of State.

Example: if you formed an LLC in Delaware on July 22, 2025, your certificate of formation lists July 22, 2025 as the effective date. That's the date you put in Form 1120 Item C and Form 5472 Item 1m. Both forms get the same date.

Match the Date Format You Used Elsewhere

Use the same date format as the tax-year fields in the same form. If Form 1120's tax-year beginning is "07/22/2025" in numeric format, Item C should also be "07/22/2025." If you used "July 22, 2025" elsewhere, use that here. Consistency within the filing.

Form 5472 may have a slightly different date format if the IRS prints the field differently, but the substantive date (the actual day/month/year) must match. The format is cosmetic; the date itself is the data point.

When You Genuinely Don't Know the Date

If you incorporated through a third-party service (Stripe Atlas, doola, Firstbase) and don't have the certificate handy, you can usually retrieve it from:

- The service's dashboard (under formation documents) - The state's online business entity search (Delaware: corp.delaware.gov; California: bizfileonline.sos.ca.gov; etc.) - The original email from the formation service confirming entity creation

The state's business entity search is the authoritative source — it shows the registered formation date directly from the state's records.

Initial Year Implications

If the date of incorporation falls within the tax year you're filing for (e.g., incorporated July 22, 2025, filing for tax year ending December 31, 2025), this is your initial year — check the Initial Return box on Form 1120 (Item E) and use the formation date as the beginning of your tax year.

The date of incorporation, the tax year beginning date, and the Item E checkbox status all reinforce each other for a first-year filing. The IRS reads them together to confirm the filing is the LLC's first year, which affects how the filing is processed.