Form 5472 for South Korea Residents with a US LLC

A Korean tax resident who owns a US single-member LLC must file Form 5472 with a pro forma Form 1120 each year the LLC had a reportable transaction with them. The US-Korea tax treaty is in force and changes nothing about that filing. Korea identifies individuals by registration number rather than a separate taxpayer number, which decides the FTIN box.

Korea-based owners arrive from two directions. Seoul and Busan founders form Delaware and Wyoming LLCs because a US entity is what Stripe, the app stores and US banks are built around. Separately, non-Korean remote workers now live in Korea on the workation visa while their LLC and customers stay on the other side of the Pacific.

Two features of the Korean position change the mechanics of the filing compared with a UK or Indian owner. A full income tax treaty is in force, which surprises owners who expect a treaty to buy relief from the form. And Korea's identification-number system gives a number to registered residents and nothing to a visitor. Neither feature removes the obligation.

If you want the filing done rather than explained, we prepare and fax the complete package from $149.

Do South Korea residents have to file Form 5472?

Yes, on the same terms as any other non-US owner. Three conditions:

1. The LLC is a US disregarded entity — a single-member LLC that has not elected to be taxed as a corporation.
2. Its sole member is a non-US person. A Korean national and a foreign national living in Korea both qualify, provided neither is a US citizen, green card holder or US tax resident.
3. There was at least one reportable transaction during the tax year between the LLC and its owner or another foreign related party.

Under Treasury Regulation § 1.6038A-1, for tax years beginning on or after 1 January 2017 and ending on or after 13 December 2017, a foreign-owned US disregarded entity is treated as a corporation separate from its owner solely for the § 6038A reporting rules. That takes no account of where the owner lives or pays tax.

Reportable transactions are money, property or services moving between you and your own LLC: contributions in, distributions out, loans either direction, payments for goods or services. Customer revenue is not reportable. A Stripe payout from a customer does not go on the form. A transfer from that Stripe balance to your personal KB Kookmin or Toss Bank account does.

For a typical Korea-based owner, that means:

• The won you converted and wired to open the LLC's US bank account — reportable contribution
• Every withdrawal you have taken to yourself since — reportable distributions
• Money you lent the LLC to cover server costs before revenue arrived — reportable loan
• Work the LLC paid your own Korean company for — reportable, and that company is a second related party with its own Form 5472

The IRS Instructions for Form 5472 state that a $25,000 penalty may apply for failure to file when due and in the prescribed manner, for a substantially incomplete Form 5472, or for failing to maintain required records. A substantially incomplete form counts as a failure to file, which is why the identifier and the Part V detail matter as much as the postmark.

Does the US-Korea tax treaty change anything?

The treaty is in force, and it changes nothing about Form 5472.

Korea appears in the K section of the IRS's income tax treaties A-to-Z list, alongside Kazakhstan and Kyrgyzstan, with its own treaty-documents page. Korean residents are therefore better placed than UAE or Vietnam owners on which country may tax what.

That advantage stops short of the information return, for a structural reason. A treaty allocates the right to tax income between two countries. Form 5472 is not a tax; it is an information return imposed by IRC § 6038A, and no treaty article exempts a taxpayer from it. The treaty may decide whether your profits are taxable in the United States, and deserves an adviser's look if you have any US presence. It is irrelevant to whether the form is due.

So do not skip the filing because someone said the treaty covers you. A treaty claim on US-source income belongs on a different form.

What goes in the FTIN box if you are in Korea on a workation visa?

The answer depends on whether Korea has ever issued you a number.

Korea identifies individuals for tax by registration number. Korean nationals hold a resident registration number. Foreign nationals who register as residents are issued a foreigner registration number, which appears on the residence card and is what they use to file through Hometax. Korea does not issue a separate standalone personal taxpayer number on top of those. A business registration number belongs to a business, not to you.

The right-hand column is identical in every row on purpose: your Korean identification status changes one box, not whether the form is due.

Where the foreign owner has no US identifying number — and most Korea-based owners have no SSN, ITIN or personal EIN — the instructions address the FTIN and a reference ID number. Leave line 4b(1) blank, put your Korean registration number in the FTIN field if you have one, and carry the same reference ID forward every year. Our FTIN and reference ID guide has the field-by-field mechanics, and do I need an ITIN for Form 5472 explains why not to apply for one to fill this box.

Unverified: we could not retrieve an English National Tax Service page stating which number the NTS expects from a foreign individual holding no Korean registration. Confirm that with the NTS or Hometax. The US side does not change: no number means "None" plus a reference ID.

Use your actual Korean address in Part II, not the LLC's registered agent address in Wilmington or Cheyenne.

Does Korean tax residency affect the US filing?

No. The Korean residency test decides what you owe Korea, and nothing about the US information return.

The threshold is 183 days. The operative definition sits in article 1-2(1)(i) of the Income Tax Act — an individual with a domicile in Korea, or who maintains a place of residence there for at least 183 days. Article 2 of the Enforcement Decree of the Income Tax Act deems a person to have a domicile in Korea where they have an occupation usually requiring continual residence in Korea for at least 183 days, or have family living with them in Korea and are deemed likely to reside there for at least 183 days in view of occupation or property. Older National Tax Service notices still describe residence as "one year or longer", reflecting pre-2015 wording; 183 days is the current Enforcement Decree.

The workation visa sits on top of that. The F-1-D workation (digital nomad) visa is open to someone working remotely in Korea for a foreign employer, with multiple entry, and the holder may not take employment or carry on profit-making activity inside Korea. The Ministry of Justice put the visa on a formal footing from 30 June 2026 and changed two of its conditions: the maximum stay rose from two years to three, and the flat income requirement of twice GNI per capita became a tiered 1× to 2× range depending on the applicant's age and where in Korea they stay — an applicant aged 18 to 34 staying outside the capital region is assessed at 1× GNI per capita (about KRW 52.41 million on a 2025 basis). Consulate pages have not all caught up, and the figure moves with published GNI, so confirm the current conditions with the Ministry of Justice or Korea Immigration before applying.

Whether a year on an F-1-D visa makes you a Korean tax resident, and how Korea then characterises your LLC's income, is a question for a Korean tax adviser or the National Tax Service. We do not advise on Korean tax. From the US side, Korean residency and any Korean tax you pay neither create nor remove the Form 5472 obligation.

How does a Korea-based owner actually file Form 5472?

You cannot e-file. A foreign-owned US disregarded entity has to send paper.

1. Prepare the pro forma Form 1120 with "Foreign-owned U.S. DE" written across the top of page 1. Only the DE's name and address and items B and E are required.
2. Prepare Form 5472 — Part I for the LLC, Part II for you with your Korean address and FTIN entry, Part III for the related party, Part IV for listed monetary transactions, and Part V with an attached statement itemising contributions and distributions.
3. Convert won to US dollars at a reasonable rate for each transaction date, applied consistently, and name your rate source.
4. Sign and fax to 855-887-7737, or mail to Internal Revenue Service, 1973 Rulon White Blvd, M/S 6112, Attn: PIN Unit, Ogden, UT 84201.
5. Keep the timestamped receipt. The IRS sends no acknowledgement; that receipt is evidence of transmission, not IRS acceptance of the return.

The regular due date for a calendar-year LLC is generally April 15, and Form 7004 extends it using the special instructions for a foreign-owned DE. Dates are in our deadline guide.

Getting it filed from Korea

Sending an international fax from Korea is a nuisance, and the Korean-specific details — the registration-number question, won conversion, a Korean company as a second related party — are what makes a self-prepared filing come back substantially incomplete.

Form5472 Prep prepares the complete package: Form 5472 with the FTIN and reference ID handled consistently, the pro forma Form 1120, and the Part V statement. A qualified tax accountant reviews each package, we fax it to the IRS Ogden PIN Unit, and we return the timestamped receipt. Late years include a reasonable cause cover letter.

$149 standard, ready in 5-7 business days. $199 express, ready within 3 business days. +$99 per additional past tax year. IRS fax delivery included.

We are not a CPA firm, we do not give tax advice, and we do not advise on Korean tax. We prepare and submit the US information return accurately.

Start your filing — about 15 minutes.

Frequently asked questions

Does the US-Korea tax treaty exempt me from Form 5472?

No. The treaty is in force and allocates taxing rights over income. Form 5472 is an information return under IRC § 6038A, and no treaty article exempts anyone from filing it.

Which Korean number goes in the FTIN box?

The registration number Korea issued you: a resident registration number for a Korean national, or the foreigner registration number on your residence card if you registered as a foreign resident. A business registration number belongs to a business, not to you.

What if Korea has never issued me any number?

Enter "None" or "N/A" in the FTIN field rather than leaving it blank, and add a self-assigned reference ID that you reuse every later year. Confirm the Korean side with the National Tax Service if you also file in Korea.

I am on the F-1-D workation visa — does that change the filing?

No. The visa governs your stay in Korea. The Form 5472 obligation follows the LLC and your non-US-person status. It does change which number you hold for the FTIN box, because registered residents are issued a foreigner registration number.

Are payments from my Korean customers reportable?

No. Customer revenue is not reportable, whoever the customer is. What is reportable is movement between you and the LLC: contributions, distributions, loans, and payments for goods or services with your own entity.

Do I need an ITIN as a Korean owner?

Not for Form 5472. The reference ID mechanism exists so owners without a US identifying number can file. Applying for an ITIN purely to complete this form adds months for no benefit.

I have owned the LLC four years and never filed — what now?

File every outstanding year as soon as you can, with a reasonable cause statement, before the IRS contacts you. Each year carries its own exposure. Our late filing guide sets out the sequence.

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A treaty in force is useful to a Korean owner, but not for this. If money moved between you and your US LLC, the Form 5472 package is due whether you are a Seoul founder or a workation-visa holder in Jeju.

File from Korea in about 15 minutes, or read the digital nomad filing guide if you split the year across countries.

Educational content only; not tax or legal advice.