Form a Delaware LLC from South Korea: Complete 2026 Guide

Delaware in one paragraph: $110 to file ($110 online), then $400 flat annual franchise tax (raised from $300 under Delaware House Bill 400, signed May 21 2026, effective retroactively for the 2026 tax year; first billed with payments due June 1, 2027), no separate annual report required each year. The state imposes no tax on LLC income earned outside the state, though the flat annual tax applies regardless of activity. Delaware does not require member names on the public formation certificate. For a South Korea-based owner the state choice mainly decides cost, privacy and paperwork, not your home-country tax result. If investor familiarity and a well-known legal framework is what you are optimizing for, Delaware deserves a close look.

The cost side of a Delaware LLC: $110 state fee ($110 online), a registered agent at typically $100-150 per year, a free IRS EIN, and a bank account that is usually free. Annual state requirement in Delaware: $400 flat annual franchise tax (raised from $300 under Delaware House Bill 400, signed May 21 2026, effective retroactively for the 2026 tax year; first billed with payments due June 1, 2027), no separate annual report required. If you use EasyBrise, Global Launch is $295 for year one (registered agent included) and $149 per year after, and for a founder in South Korea the whole first year typically comes in well under $500.

Delaware fits if you're planning to raise US venture capital or want the state most investors and legal counsel are already familiar with, and you're comfortable with the flat $400 annual tax (raised from $300 by 2026's House Bill 400) regardless of your LLC's size. Check the comparison table above before you commit, as switching later is not a simple amendment: the Delaware LLC would be dissolved and a new one formed elsewhere.

Your Delaware LLC exists once the state accepts the filing, but it is only ready to trade after these steps: sign the Operating Agreement; get the bank account open; apply for payment processors; calendar your Delaware annual obligation ($400 flat annual franchise tax (House Bill 400, raised from $300), first billed with payments due June 1, 2027) and the federal Form 5472 and pro forma 1120. On BOI: FinCEN's rule in force since August 14, 2026 permanently exempts all US-formed LLCs, so there is nothing to file there.

South Korean freelancers, developers, consultants and online sellers form US LLCs to invoice international clients in dollars, hold a US business bank account and present a domestic US vendor to American customers. A founder in Korea funds the LLC from won converted to dollars. Korea's controlled-foreign-company rules start at a low ownership level and look at the effective tax the entity pays, so the Korean tax analysis is the main task.

Here is how Delaware formation works for someone in South Korea. File the Articles of Organization with the Delaware Secretary of State, using a registered agent's physical Delaware address. Request your EIN from the IRS, writing "Foreign" or "N/A" in place of an SSN (phone: 267-941-1099, about 45-60 minutes; fax or mail: 4-6 weeks). Then apply for Mercury or Relay online. Every step can be done remotely.

A South Korean founder planning to raise US capital or sell to a US acquirer may choose Delaware despite the $400 annual tax, because investors know the law. The $400 is a fixed amount for a Korean budget.

Over five years, the state-level cost of a Delaware LLC is a $110 filing fee plus $400 a year for five years, so $2,110 in total, before the registered agent. That makes Delaware the most expensive of the five states on this measure. The same arithmetic across the five states runs from $50 to $2,110. For a South Korean owner, the low threshold of the controlled-foreign-company rules is the central issue, so budget for a Korean tax adviser's written view alongside the US costs.

The test looks at the foreign corporation's average effective income tax rate over the three most recent consecutive years and applies where it is 17.5 percent or less. That figure is 70 percent of the 25 percent top marginal corporate rate and applies from tax years beginning on or after 1 January 2026. A non-resident-owned single-member LLC earning only non-US-source income usually owes no US federal income tax, so its effective rate can be near zero. The summary mentions no active-business exclusion, so ask your adviser whether one applies.

As a South Korean owner, your recurring dates look like this. State: Delaware's $400 annual tax is first billed with payments due June 1, 2027, and there is no separate annual report. Federal: Form 5472 with the pro forma Form 1120 is due on the return due date, April 15 for a calendar-year LLC, extendable with Form 7004. For the one-off EIN call, the IRS line (6 a.m. to 11 p.m. Eastern) is open 8 p.m. to 1 p.m. Korean time in US standard time (7 p.m. to noon in US daylight time). Put the state date and the federal date in your calendar when the EIN arrives, because a missed Form 5472 carries a $25,000 minimum penalty.

PwC's August 2026 news flash on Korea's tax reform proposals says the low-tax threshold would fall from 17.5 percent to 15 percent to align with the global minimum tax rate, with most changes taking effect from January 2027 if the National Assembly approves. Even a lower threshold leaves a zero-tax LLC inside the test, so the proposal does not remove the question. Check the status of the bill with a Korean adviser.

The United States and South Korea have an income tax treaty in force. It covers dividends, interest, royalties and tie-breaker rules for residency, and you can confirm the details in the IRS treaty tables. For a typical founder whose LLC earns only non-US-source income, the treaty changes little in practice because there is usually no US federal income tax for it to reduce.

PwC's Korea summary says a Korean national or company that directly or indirectly holds at least 10 percent of a foreign corporation is covered, so an individual is within the wording, although the page does not define national or address residency. The test is whether the foreign corporation's average effective income tax rate over the three most recent consecutive years is 17.5 percent or less, which is 70 percent of the 25 percent top corporate rate for tax years beginning on or after 1 January 2026. If it applies, undistributed earnings are deemed paid as a dividend to the Korean shareholder. A single-member LLC that bears little or no US federal tax sits on the wrong side of that test, so a Korean adviser must model it.