If you are setting up a small consultancy or professional practice in Korea, the comparison you have probably been given is a rate table. It is misleading at this size. Here is what actually decides it — including the one item most comparisons leave out entirely.
“Korean corporate tax starts at 10% and personal rates go to 45%, so obviously incorporate.” This is the reasoning almost everyone arrives with, and at small scale it is wrong twice over. It ignores where the personal brackets actually bite, and it ignores the second layer of tax that applies when the money reaches you.
Korean personal income tax is progressive from 6% to 45%, but the punishing brackets start higher than most people assume. The 35% bracket begins at a taxable income of roughly KRW 88 million, and 40%+ above roughly KRW 300 million. Below that you are in the 15% or 24% band, and the gap against a company is modest.
This is the part that reverses the conventional answer. Corporate profit is taxed at the company level, and taxed again when it reaches you — as salary, or as a dividend. If you take everything out each year, the second layer cancels the lower first-layer rate, and the company can cost more than the sole proprietorship.
The corporate rate advantage is real only if you intend to leave profit inside the company. If the business income is your living costs, there is nothing to leave. This single question — do you retain, or do you withdraw — moves the answer more than the rate table does.
At small scale this difference is frequently larger than the tax difference, and it is almost never in the comparison you are shown.
| Company, with a remunerated director | Sole proprietor, no employees | |
|---|---|---|
| Your status | Workplace subscriber — a company's directors and officers are included in the definition of “employee” for health insurance | Regional subscriber — the proprietor of a business with no employees is excluded from workplace coverage |
| Contributions calculated on | Remuneration only | Income and property |
| Non-working spouse | Can be registered as your dependent. For a foreign national spouse the usual residence-period requirement is waived | Assessed within the same household — not covered as a dependent |
If you own your home in Korea, a regional subscriber is charged on it every year regardless of income. After a basic deduction of KRW 100 million of property tax base:
| Property tax base | Annual property component |
|---|---|
| KRW 100 million or below | Nil |
| KRW 200 million | approx. KRW 1.1 million |
| KRW 300 million | approx. KRW 1.5 million |
A remunerated director of a company pays nothing on property. For someone who owns a home and has a non-working spouse, this pair of differences can outweigh the entire tax comparison — and it is invisible in a rate table.
Five reasons are usually given. Only some of them are switched on at small scale.
| Reason | When it actually applies |
|---|---|
| Rate difference | Only once taxable income passes roughly KRW 88 million. Below that it is largely theoretical |
| Retaining profit | Only if you leave money in the business. If you withdraw everything, double taxation works against you |
| Credibility and contracting | Often the only one that applies early. Public tenders, large-company supply chains, government programmes and some overseas clients deal only with companies |
| Raising money | A sole proprietorship has no shares to give. Relevant only if you intend to bring in investors |
| Succession, splitting ownership | Shares can be gifted or divided. Rarely relevant at the outset |
Separation. A company's funds, expenses and revenue must be kept strictly apart from your own — separate account, documentation, payroll processing for your own salary, corporate formalities. For a one-person operation this is a real cost in attention, not merely in fees. Setup and annual running costs are both materially higher.
One threshold worth knowing. A sole proprietor whose revenue reaches a statutory level must have a tax agent certify the return; for professional, scientific and technical services that level is KRW 500 million. The certification process is demanding, and it is common practice to incorporate before reaching it rather than after.
Five signals, in the order they usually arrive.
| # | Signal |
|---|---|
| 1 | Credibility and contracting — a client, tender or programme requires a company |
| 2 | Tax and health insurance pressure — taxable income past the 35% bracket, with regional-subscriber contributions on top |
| 3 | Approaching the certification threshold above |
| 4 | Raising money — someone wants equity |
| 5 | Succession or splitting ownership |
For most small consultancies the first signal arrives well before the others. Which means you will usually convert because a client asks you to, not because of tax. Planning on that basis is more realistic than planning on a rate projection — and it means starting simple is rarely a mistake, provided the conversion is modelled before the decision rather than after. Converting carries its own tax consequences.
The order that works: establish what you will actually withdraw versus retain; check whether you own property in Korea and whether a spouse would be a dependent; then ask whether any client or programme in your pipeline requires a company. Those three answers settle it in most cases, and none of them is on the rate table.
We advise foreign nationals and foreign-invested businesses in English end to end, from the initial form through registration and ongoing compliance. If you are deciding, a short written exchange about income level, property and client type is usually enough for a clear recommendation.
Basis. This note reflects the Income Tax Act (progressive rates; the certification requirement and its revenue threshold under the Enforcement Decree), the Corporate Income Tax Act (corporate rates), and the National Health Insurance Act and its Enforcement Decree (inclusion of a company's directors and officers as employees; exclusion of the proprietor of a business without employees from workplace coverage; assessment of regional subscribers on income and property; the property points scale and basic deduction; and the waiver of the residence-period requirement for a foreign national dependent). Contribution rates are those current for 2026. It is general information as at September 2026, not advice on a specific situation. Please take advice before acting.
Not at the size most people are asking at. Two things break that reasoning. First, the personal progressive rate only becomes punishing above a taxable income of about KRW 88 million, where the 35% bracket starts — below that you are in the 15% or 24% band and the gap is small. Second, and more importantly, a company is taxed twice: once on its profit and again when the money reaches you as salary or dividend. If you take everything out each year, that second layer cancels the lower first-layer rate and a company can end up costing more than a sole proprietorship. The corporate rate advantage is real only if you intend to leave profit inside the company.
It is often larger than the tax difference at small scale, and most comparisons omit it. A director of a company who draws remuneration is treated as an employee for national health insurance, so contributions are calculated on the remuneration only. A sole proprietor with no employees is excluded from workplace coverage and becomes a regional subscriber, whose contributions are calculated on income and property. If you own your home in Korea, the property component is charged every year regardless of what you earn — on a property tax base of KRW 200 million it is roughly KRW 1.1 million a year, and around KRW 1.5 million at KRW 300 million, after a KRW 100 million basic deduction. A remunerated director pays nothing on property.
This is the second half of the same point, and it usually surprises people. If you are a remunerated director of a company you are a workplace subscriber, and a non-working spouse can be registered as your dependent — and for a foreign national spouse the usual residence-period requirement is waived. If you are a sole proprietor you are a regional subscriber and your spouse is assessed in the same household rather than covered as a dependent. Where the spouse has no income of their own, this difference alone can outweigh the tax comparison.
Two things. A company's money must be kept strictly separate from yours — separate account, documentation, payroll processing for your own salary, and corporate formalities. For a one-person operation that is a real cost in attention, not just fees. Setup and annual running costs are both meaningfully higher than for a sole proprietorship. Against that, there is a threshold worth knowing: a sole proprietor whose revenue reaches a statutory level must have a tax agent certify the return — for professional, scientific and technical services that level is KRW 500 million. It is common practice to incorporate before reaching it.
Five signals, in the order they usually arrive. (1) Credibility and contracting — public tenders, large-company supply chains, government programmes and some overseas clients deal only with companies. (2) Tax and health insurance pressure, once taxable income passes the 35% bracket. (3) Approaching the certification threshold above. (4) Raising money — a sole proprietorship has no shares to give. (5) Succession or splitting ownership. For most small consultancies the first signal arrives well before the others, which means you usually convert because a client asks you to, not because of tax.
Professional services to overseas clients are zero-rated only where that country grants the same exemption to Korean providers — and the account the money lands in matters too.
Read the guideTell us roughly what the business will earn, whether you own property in Korea, and what your clients look like. Those three facts usually settle it.