Why Foreign-Owned LLCs Ignore the Standard Form 1120 Mailing Address

Why Two Mailing Addresses Exist on the Same Filing

When you file Form 5472 + pro forma Form 1120 for a foreign-owned single-member LLC, you're submitting a single envelope that conceptually contains two forms. Each form has its own published mailing address in its respective IRS instructions:

- Form 1120 instructions: list multiple regional service centers (Kansas City, Ogden, Cincinnati) based on the corporation's principal business location and total assets. - Form 5472 instructions: list a single address — the dedicated PIN Unit at Ogden, Utah — regardless of business location or asset size.

These two addresses are different. The Form 1120 address might be Kansas City. The Form 5472 address is always Ogden. You cannot mail to both. You must pick one.

The Standard Form 1120 Mailing Address (and Why It's a Trap)

If you instinctively follow the Form 1120 instructions — which is the natural thing to do, because the envelope is technically a Form 1120 filing — you'll mail to one of the standard Form 1120 service centers. As of 2026, the relevant addresses depend on your corporation's location and assets, but the most common is:

Department of the Treasury Internal Revenue Service Kansas City, MO 64999-0012

This is the trap. Kansas City processes regular C-corporation returns. They are not equipped to handle the Form 5472 attachment.

What happens when a foreign-owned LLC's pro forma 1120 + 5472 arrives in Kansas City:

1. The mail clerk sees a Form 1120 cover. Routes to standard corporate processing. 2. The processor opens the envelope, finds an essentially blank Form 1120 and an attached Form 5472. 3. Depending on the processor's training, the filing is either (a) forwarded to Ogden, which can add weeks, (b) treated as substantially incomplete and bounced back, or (c) lost.

None of these outcomes is good. The §6038A timely-filing deadline is calculated on receipt by Ogden, not receipt by Kansas City. A Kansas City detour can push your filing past the deadline.

The Form 5472 Mailing Address: Ogden PIN Unit

The Form 5472 instructions (latest revision at irs.gov/pub/irs-pdf/i5472.pdf) specify a dedicated mailing address — the Ogden PIN Unit:

Internal Revenue Service 1973 N. Rulon White Blvd. M/S 6112 Attention: PIN Unit Ogden, UT 84404

The PIN Unit is a specialized processing team within the Ogden Service Center. They handle Form 5472 filings as their core workload. Their mail intake is configured to recognize foreign-owned LLC filings and route them to the right processor.

The physical address (1973 N. Rulon White Blvd) differs from the standard IRS Ogden P.O. Box. This matters for §7502(f) Private Delivery Services (DHL, FedEx, UPS) because they cannot deliver to P.O. Boxes — they need a street address. The 1973 N. Rulon White Blvd address is street-deliverable. Use it for DHL/FedEx/UPS shipments.

The Decision Rule: 5472 Cover Always Wins

The rule is simple: when filing Form 5472 + pro forma Form 1120 for a foreign-owned single-member LLC, follow the Form 5472 mailing address. Ignore the Form 1120 mailing address entirely.

This is one of the few situations in tax compliance where you intentionally disregard a form's published instructions. The reason: the IRS has explicitly carved out a dedicated processing channel for Form 5472 because of its specialized nature (§6038A reporting from foreign-owned entities). The Form 1120 channel was not designed for this filing pattern.

Think of it this way: the pro forma 1120 is a structural envelope around the Form 5472. The substantive filing is the Form 5472. Therefore, the mailing address that matters is the Form 5472 address.

If you have any doubt, check the Form 5472 instructions directly. They state explicitly: 'Where to file. File Form 5472 with the income tax return of the reporting corporation by the due date (including extensions) of that return.' Then they direct you to mail the combined package to the Ogden PIN Unit.

Common Mistakes That Get the Package Rerouted (or Lost)

Six common mistakes that misdirect Form 5472 filings:

1. Mailing to the standard Form 1120 service center. As discussed above. Always use the Ogden PIN Unit address.

2. Using the wrong Ogden P.O. Box. Some older sources list 'Ogden, UT 84201-0012' or '84409' — these are different IRS Ogden facilities. The PIN Unit is specifically at 1973 N. Rulon White Blvd, 84404.

3. Not writing 'Foreign-Owned U.S. DE' at the top of the pro forma 1120. Without this header, the Ogden intake team may misroute the package to a different Ogden processing line.

4. Listing the LLC's foreign owner's address on the Form 1120 entity block. The entity block should show the LLC's address — the same address used on Form 5472 Part I. The foreign owner's address goes elsewhere (Form 5472 Part II).

5. Forgetting to attach Form 5472 entirely. If only the pro forma 1120 arrives, the Ogden PIN Unit cannot process it as a Form 5472 filing. It gets bounced to standard corporate processing and likely lost.

6. Including non-required schedules (Schedule G, M-3, etc.). The pro forma 1120 should have only the front cover page. Extra schedules can confuse the intake team and slow processing.

Double-check all six before sealing the envelope.