What the Business registration number is
The Business registration number is the number National Tax Service (NTS) assigns to a taxpayer in South Korea. It follows you across every tax you deal with: VAT, income tax and withholding. Businesses that pay you will ask for it before they release payment, because they report their suppliers to National Tax Service (NTS) by this number.
Who needs one
Everyone who supplies goods or services as a business in Korea, taxable or tax-exempt, and separately for each place of business. Apply before you start or within 20 days of starting. A company files the registration with its incorporation report.
How to register, step by step
- Gather the papers: the 사업자등록신청서, the lease if you rent the premises, any licence your trade needs, and a partnership agreement if there is more than one owner.
- Decide on the form whether you are a general or a simplified taxpayer. An individual expecting under KRW 104 million a year can take 간이과세; for property letting and taxable entertainment venues the line is KRW 48 million.
- File on Hometax under 국세증명·사업자등록·세금관련 신청/신고 → 사업자등록 신청, attaching photographs of the papers, or take them to the 민원봉사실 at any district tax office.
- Do it within 20 days. Register late and you pay 1% of everything you supplied between starting and the day before you applied, 0.5% as a simplified taxpayer, and 2% for registering in someone else's name.
- Collect the 사업자등록증 within two days. The office may take five more if it wants to inspect the premises.
How to find or check a Business registration number
Hometax → 사업자등록 상태조회 returns whether a business is trading, suspended or closed, and its tax type. NTS publishes the same service as an open API on data.go.kr, with a 진위확인 call that checks a number against the opening date and the representative's name. It syncs every 30 minutes, so a new registration takes a day or two to appear.
Documents, cost and how long it takes
The business registration application (사업자등록신청서) is filed at any tax office or on Hometax. An individual business adds a copy of the lease if premises are rented, a copy of any licence or permit the trade needs, and the partnership agreement if there are several owners. Fuel retailers, scrap-material collectors and taxable entertainment venues also give a statement of the source of funds. A foreign national adds an alien registration or passport copy, and a tax representative appointment if staying abroad more than six months. A for-profit corporation files its incorporation notification with the application, together with the lease in the company's name, shareholder details, any licences, an in-kind contribution statement if relevant, and a multiple-location statement if it wants taxation by business unit. The tax office issues the certificate within two days of application, extendable by five days if it needs to inspect the premises.