How to get a Business registration number in South Korea
Who needs a Business registration number in South Korea, how to register with National Tax Service (NTS), what the number looks like, how to find or check one, and where it goes on your invoices.
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Updated for 2026
Last reviewed September 2026
This is the general edition of this guide for South Korea. It explains how the Business registration number, VAT and annual filing work and names National Tax Service (NTS) as the place to confirm thresholds and dates. Country-specific figures are added as each edition is reviewed.
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
Anyone who earns taxable income, runs a business, employs staff or wants to be paid by a company that must report its suppliers. In practice, if you invoice, you need one.
How to register, step by step
Gather your identity document and, for a business, the registration certificate and the owners' or directors' details.
Register with National Tax Service (NTS). Choose the taxes you will be liable for; do not add VAT unless you must or want to register for it.
Download or collect the registration certificate. It shows your Business registration number; keep the PDF, because clients will ask for it.
Add the Business registration number to your invoice template and letterhead.
How to find or check a Business registration number
Your own number is on the registration certificate and on every letter or notice from National Tax Service (NTS). Most authorities now offer an online lookup to confirm a supplier's number and registered name before you pay them; use it for any new supplier.
Where it goes on your paperwork
In the invoice header next to your business name, and in the client block when the client is a registered business. Quotations and purchase orders carry it too, so the client's accounts team can match documents. The South Korea invoice generator has a Business registration number field in both blocks.
Questions people ask
Does it cost anything to get a Business registration number?
Registration with National Tax Service (NTS) is normally free. Agents charge for filling in the same form; pay one only if you want the time saved.
Can I invoice without a Business registration number?
You can write the document, but many clients will not pay an invoice that has no Business registration number, and you cannot charge VAT without being registered. Register first; it is usually quick.
Is the Business registration number the same as VAT registration?
Not necessarily. The Business registration number identifies you as a taxpayer; VAT registration is a separate status you take on when turnover passes the threshold or you opt in. Some countries use one number for both, others issue a separate VAT number.
How long does registration take?
Online registrations are often instant or take a few days; applications that need a visit or document checks take longer. Start before you need to send your first invoice.
Sources
National Tax Service (NTS) — the official guidance for South Korea
How this guide was made
Written from published tax-authority guidance and reviewed on 2026-09-03. Everything here is indicative rather than a ruling on your circumstances, and rules change. Confirm anything you rely on with National Tax Service (NTS) before acting on it, and tell us if you find something out of date so we can correct it.
This guide explains the rules in general terms and is not tax advice for your circumstances. Confirm your position with a qualified adviser or with National Tax Service (NTS).
🇰🇷 South Korea
Tools for South Korea
Invoices, quotations, purchase orders, credit notes and waybills in KRW, with VAT and the Business registration number on the document. Plus a VAT calculator. Everything runs in your browser and nothing is uploaded.