Field note 08 · 현장 수첩

The Business Number Checks Out — What That Proves, and What It Doesn't

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You did the sensible thing. You asked for the business registration number, you put it into a Korean government page, and it came back active. Now you feel better — and that feeling is the part I want to talk about, because a clean lookup answers a narrower question than most people think it does. It tells you a registration exists and is alive. It does not tell you that the person in your inbox is the business behind it.

Two situations bring people to me after a lookup "passed." In the first, the other side never sent a number at all — they sent a photograph of a certificate. In the second, they sent a real number that checked out fine, and it turned out not to be theirs. Both are handled below, and neither is handled by staring at the document.

0. What a lookup is actually answering

Every check in this note answers a question about a registration — a record in a government file. None of them answer a question about the person messaging you. Keep those two apart and the rest of this is easy; blur them and a passing lookup becomes the thing that talks you into sending money. When a result comes back clean, the honest sentence is "this number belongs to a business that exists and is currently active" — not "this person is legitimate."

1. The status check — a real answer to a small question

Korea's National Tax Service has a status lookup that works with no login and no Korean ID: Hometax status lookup. Feed it a 10-digit business registration number and it tells you whether the registration is 계속사업자 (active), 휴업자 (suspended), or 폐업자 (closed). That is genuinely worth having. Somebody taking orders today on a registration the tax office lists as closed has just answered your question for you, and no amount of explanation fixes it.

Read the boundary carefully, though: what comes back is a status. It is an answer about the number you typed in, not about who typed it to you. I'll be straight about the limit of my own checking here — I was not able to confirm from outside Korea what the page hands back besides the status, so I'm not going to tell you it does or doesn't show you a registered name to compare against. Don't build on what it might return. Build on the register in the next section, which I could read.

2. The register that ties a number to a name — and to a website

For online sellers there is a second register, and it is the one that catches a borrowed number: the Korea Fair Trade Commission's 통신판매사업자 등록현황. No login. Search by business number, company name, or representative. What comes back is a row: 상호 (registered name), 대표자 (representative), 도메인 (domain), 운영상태 (operating status), 신고일자 (filing date).

The domain column is the one that does the work. A scammer who wants a number that survives a lookup doesn't invent one — inventing is the amateur move. They copy a real one out of some real company's website footer, where Korean law requires it to be printed. That number is genuine. It will come back active. And it will come back attached to a name and a domain that have nothing to do with the shop or the person in front of you. Field note 05 makes this same move in one line; here is where it stops working, and what to do then.

It stops working the moment the other side isn't an online seller. This register covers 통신판매업자 — mail-order and e-commerce sellers — and nobody else. A recruiter, a consultancy, a factory, a landlord, a private individual: none of them are required to be in there, so none of them will be. If your search returns nothing, you have learned that this person isn't a registered e-commerce seller. You have not learned that they're a fraud. Reading an empty result as a verdict is its own way of getting things wrong.

3. When they send a picture instead of a number

Ask for a business registration number and you will sometimes get a photo or a PDF of a 사업자등록증 instead. It looks official. It has a stamp on it. And I am not going to teach you to examine it — not the seal, not the layout, not the typeface. That road is a dead end for you and a training exercise for them: anyone who produced one convincing image can produce a better one, and you'd be betting money on an eye you have no reason to trust. A picture is not a lookup.

Do this instead. Read the number off the image and run it through sections 1 and 2. The image stops being evidence and becomes what it actually is — a delivery mechanism for a number you were going to check anyway. Everything above applies unchanged.

Then make a better request. Korean government documents issued online carry a 문서확인번호 — a document confirmation number — printed on the document itself, and there is a public page at gov.kr with a single field where anyone can type that number in and confirm the document came from where it claims. No login, no Korean phone, no ID. That is the difference that matters: a snapshot of a certificate has nothing to check it against, while a document issued with a confirmation number is checkable by design. So don't ask for a picture of anything. Ask for an issued document with its confirmation number — and if what comes back is another photograph, or a number that returns nothing, you have your answer without having examined a single stamp.

One caveat I'd rather state than leave you to discover: which office issues which certificate varies, and I could not confirm from here whether every tax-office certificate routes through that particular page. The principle survives the detail. Documents that carry their own verification number can be verified; photographs cannot.

4. The check that exists, and that you can't run

There is a check that would settle it for any business, not just online sellers. The tax office operates a matching service: give it a business registration number together with the representative's name and the opening date, and it reports whether those three agree with its records. That is precisely the check a borrowed number fails, because the borrower has the number but not the pair of facts attached to it.

You cannot use it. It is published as a developer interface that requires a registered key on Korea's public data portal — not a page you can visit and type into. I'd rather tell you it exists and is out of reach than let you go looking for a door that isn't there.

It is still worth knowing, for one reason. Those three fields — number, representative's name, opening date — are what a real business can give you in about ten seconds, because they're printed on its own registration. So ask for all three. Understand exactly what you're buying: not verification, but friction. A person recycling a number lifted from a footer now has to invent two more facts that have to agree with each other, and invented facts tend to arrive slowly, or with an explanation attached. That's a signal, not a proof. Treat it as one.

5. What none of it proves

Put the whole sequence together and here is what you're holding: a registration that exists, is active, and — if they're an online seller — is attached to the name and domain in front of you. That is a real result and it's more than most buyers ever get. It is also silent on every question that comes next. Whether the goods exist. Whether the person answering your messages is the person on the registration. Whether anything ships. A registry records that a business was set up; it doesn't watch what the business does afterwards.

Which is the honest place to end. The checks in this note are the ones that work from where you are, and I'd rather you run them knowing their edges than trust a green result that was answering a smaller question all along.