Most foreign business owners in Korea hit the same wall: the English-language guides are vague, the NTS portal is in Korean, and by the time you figure out what you actually needed to do, you’ve already missed a deadline.
This guide gives you the practical sequence: who registers, when, how, what invoices you must issue, when refunds are realistic, and where the real traps are. It covers VAT specifically—not corporate tax, not income tax.
Covered in this guide: – Registration thresholds and timing rules for 2026 – Step-by-step filing and invoice requirements – VAT refund eligibility and the documentation that makes or breaks a claim
Who Needs to Register for Korean VAT—And When
Korean VAT for foreign businesses operates under the 부가가치세법 (Value Added Tax Act), which applies to any business supplying goods or services in Korea—regardless of whether the owner is Korean. Residency status matters for how you register, not whether you register.
If you are running a business in Korea, assume VAT applies to you until you confirm otherwise.
Turnover Thresholds: The KRW 30 Million Exemption Rule
Korea has a simplified taxpayer (간이과세자) category for small businesses. As of 2026, the simplified-taxpayer threshold is KRW 104 million in annual revenue (raised from KRW 80 million in 2024). Verify the current figure at the National Tax Service (국세청, NTS) website (nts.go.kr), as this threshold has been revised upward in recent years and may change again. Businesses below that level may qualify for simplified VAT treatment, which has a reduced effective rate and simplified filing.
Separately, simplified taxpayers with annual revenue below KRW 48 million are exempt from paying VAT (납부면제) — but must still file. Note this is a payment exemption, not VAT-exempt (면세) status. Exemption applies to specific goods and services (basic foodstuffs, certain medical services, educational services). If you are selling software, consulting, or most business services, you are not exempt just because you are small.
VAT exemption (면세) is category-based — it covers specific goods/services listed in the law (basic foodstuffs, certain medical and education services), not “small businesses.” A B2B software, consulting, or general service business is not exempt regardless of revenue. The practical rule: most foreign-run B2B service businesses should register as a general taxpayer (일반과세자) from the start. Retrofitting later is painful.
Non-Resident vs. Resident Business Distinctions
A resident business (domestic entity: 법인 or individual business with 사업자등록증) registers at the local tax office (세무서) covering its business address.
A non-resident or foreign business supplying digital services or electronic services to Korean consumers may be required to register under the simplified registration system for foreign businesses (간편사업자등록). This applies to platforms like foreign SaaS products or digital content sold directly to Korean end-users. The NTS (국세청) maintains a separate portal for this; verify the current URL and registration requirements at nts.go.kr/english.
If you have a physical presence in Korea (an office, a branch, a registered address), you register the standard way—same as a Korean business, just with additional foreign identification documents.
Grace Period and Retroactive Registration
You are required to register before or at the point you begin business activities—not after you’ve made your first sale. According to the Value Added Tax Act (부가가치세법) Article 8, the NTS allows registration within 20 days of commencing business; verify the current provision, as enforcement nuances can shift.
If you missed that window and have been operating unregistered, retroactive registration is possible but triggers a review of uncollected and unremitted VAT. Penalties apply. The sooner you regularize, the lower the exposure.
The VAT Registration Process: Step-by-Step
Required Documents
For a foreign national registering a business in Korea, standard documents include:
- Valid passport (and ARC if you are a resident)
- Business registration application form (사업자등록신청서)
- Lease agreement or proof of business address in Korea
- Description of business type (업태) and category (종목)
- Bank account information (Korean account preferred; some offices require it before issuance)
- For corporations: articles of incorporation, corporate seal (법인 도장), and certificate of incorporation
Foreign nationals without an ARC will need additional identity verification. In some cases, the tax office requires a Korean-speaking representative or a tax agent (세무대리인) to be on file.
Where to File
Two options:
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In-person at the local tax office (세무서): Find the office with jurisdiction over your business address. This is the more reliable path for first-time registrants with complex situations—you can ask questions on the spot, even with limited Korean.
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Online via the NTS Hometax portal (홈택스, hometax.go.kr): Requires a valid Korean public certificate (공동인증서 or 금융인증서) and Korean-language navigation. Manageable if you have basic Korean or a bilingual accountant guiding you. The NTS (국세청) publishes English-language guidance documents; verify current availability and scope at nts.go.kr/english, as the English portal content is updated periodically.
For most foreign founders doing this for the first time, in-person is faster despite appearances.
Timeline from Submission to Issuance
Standard processing time is 2–5 business days for straightforward registrations. The 사업자등록증 (Business Registration Certificate) is issued once approved—this is not the same as your VAT certificate, but it covers both.
Complex cases (foreign entity, no ARC, virtual office address) can take 2–3 weeks if the tax office requests additional documentation. Build this into your launch timeline. You cannot legally issue tax invoices until the registration is complete.
What Most Guides Get Wrong About Korean Tax Invoices
The NTS system rejects invoices issued even one day outside the allowed window—”close enough” does not exist in Korean VAT.
Invoice Format and NTS Certification Requirements
Korean tax invoices (세금계산서) must be issued electronically through the NTS e-invoicing system (전자세금계산서). Paper tax invoices still technically exist in law but are not accepted in standard B2B transactions. The electronic system requires your NTS-registered credentials and your counterparty’s business registration number.
The invoice must include: your business registration number, counterparty’s registration number, transaction date, supply value, and VAT amount (separately stated). Missing any of these fields results in the invoice being invalid for the buyer’s input tax deduction—which means your client will ask you to reissue it, creating friction and potential late-filing problems.
Timing Rules That Catch Foreign Business Owners
The supply date (공급시기) determines when a tax invoice must be issued. For most services, this is the date of supply or the date of completion. For goods, it follows the delivery date.
You must issue the tax invoice by the 10th of the month following the supply month. This is a hard deadline. The NTS system rejects late invoices. If you miss it, you can file an amended return, but there are penalties—typically 1% of the supply value as of 2026; verify the current penalty rate under 부가가치세법 Article 60, as penalty structures are subject to legislative revision.
Foreign business owners often operate on payment-date logic (invoice when paid). Korean VAT operates on supply-date logic. These are different things. The gap between when you delivered a service and when your client pays you is irrelevant to invoice timing.
When You Don’t Issue a Tax Invoice
You do not issue a tax invoice for: – Sales to non-business consumers (B2C): you issue a cash receipt (현금영수증) or a credit card receipt instead – VAT-exempt supplies (면세) – Zero-rated exports (영세율): you still file these, but the invoice process differs
Many foreign founders assume every sale needs a tax invoice. B2C sales to Korean consumers work differently—you register for the cash receipt system (현금영수증 가맹점) separately.
Quarterly VAT Filing: Deadlines and Thresholds for 2026
General taxpayers (일반과세자) file VAT twice a year (semi-annual confirmed returns), with interim preliminary returns each quarter. The 2026 schedule below reflects the standard NTS calendar; always verify exact dates at nts.go.kr before each deadline, as dates falling on weekends or public holidays may shift.
| Period | Filing Deadline |
|---|---|
| Q1 (Jan–Mar) | April 25 |
| Q2 preliminary | July 25 |
| Q3 (Jul–Sep) | October 25 |
| Year-end final | January 25 (following year) |
Filing Windows and Late-Submission Penalties
Filing late triggers a 10% penalty on underpaid tax plus daily interest. The overdue interest rate applicable to national taxes is set annually by the Ministry of Economy and Finance (기획재정부); as of recent years it has been in the low single digits annualized, but verify the current rate under the Framework Act on National Taxes (국세기본법) at nts.go.kr before assuming any specific figure. The penalties are not crippling for small amounts, but late filings are flagged in the system and increase audit risk.
Calculating Taxable vs. Tax-Exempt Sales
Your net VAT payable = output VAT (collected from customers) minus input VAT (paid to suppliers). Standard rate is 10%.
Keep your purchase receipts and input tax invoices organized by quarter. Input VAT on business expenses (office rent, equipment, professional services from registered Korean businesses) reduces your liability. Input VAT on non-business expenses or improperly documented purchases is rejected.
Working with an Accountant vs. DIY
The NTS Hometax system works. It is, however, entirely in Korean, and the error messages are not self-explanatory. A bilingual accountant (세무사) typically charges in the range of KRW 100,000–300,000 per quarter for basic VAT filing for a small business, based on publicly reported market rates as of 2026—verify current rates with Korean accountant directories or expat business communities, as fees vary by firm and complexity.
If your situation is simple (single entity, domestic-only sales, no export refunds), DIY is feasible once you’ve done it once. If you have cross-border transactions, export refund claims, or mixed taxable/exempt sales, pay for an accountant.
Claiming VAT Refunds as a Foreign Business Owner
Refund Eligibility
VAT refunds arise when your input VAT exceeds your output VAT—most commonly for businesses with significant export sales. Export sales qualify for zero-rate (영세율) treatment, meaning you charge 0% VAT to the foreign buyer but can still reclaim input VAT you paid domestically.
To qualify, you need documented proof that goods or services were supplied outside Korea: export declarations (수출신고필증) from Korea Customs Service (관세청, customs.go.kr) for goods, or for services, contracts and payment records showing foreign-entity counterparties. Confirm current documentation requirements with the Korea Customs Service (관세청) directly, as evidentiary standards for service exports in particular can be interpreted with some discretion.
Export-Stage Refund Process and Timelines
File the refund claim with your regular VAT return. According to NTS guidance, standard export refund claims are processed within approximately 30 days, with more complex cases potentially extending to 60 days pending additional verification; verify current processing timelines at nts.go.kr, as operational timelines can change.
Refunds are deposited to your registered Korean bank account. Refund claims over a certain threshold trigger automatic review, not necessarily a full audit.
Common Rejection Reasons
- Export documentation missing or mismatched with invoice dates
- Services claimed as exports but with Korean-resident end-users (residency of the recipient matters for service exports)
- Input VAT claimed on non-business or entertainment expenses
- Invoice irregularities—your supplier issued an invalid invoice, making your input VAT uncreditable
The last point trips up a lot of people: if your landlord or supplier gave you an improperly formatted invoice, that’s your problem at refund time, not theirs.
Documentation and Compliance Red Flags
Record Retention
Korean tax law requires retention of all tax-related documents for 5 years from the end of the taxable year, under the Framework Act on National Taxes (국세기본법); verify the current retention period and any category-specific variations at nts.go.kr. This includes electronic invoices, bank statements, contracts, and import/export declarations. Digital storage is accepted; the NTS e-invoicing system automatically archives your issued invoices.
Audit Triggers for Foreign Businesses
Businesses flagged for VAT audit typically share these patterns: – Consistent large refund claims with thin documentation – Revenue on tax invoices inconsistent with bank deposits – Late or amended filings in multiple consecutive periods – First-year foreign business with large input VAT claims and minimal output VAT
An audit (세무조사) is not automatically a crisis, but foreign owners who don’t have documentation in order—and can’t navigate the process in Korean—end up with larger adjustments than necessary.
Currency and Cross-Border Payment Documentation
If you receive payments in foreign currency, document the exchange rate used at the time of each transaction. The NTS generally accepts Bank of Korea (한국은행) base rates or major commercial bank rates (such as KEB Hana Bank) for conversion purposes; verify the currently accepted conversion methodology at nts.go.kr, as accepted rate sources can be updated. Inconsistent or undocumented conversion methods are a common audit adjustment point.
Non-Resident Business Owners: Special Rules
Tax Treaty Implications
Korea has tax treaties with over 90 countries as of 2026. These treaties primarily affect income tax and withholding tax, not VAT directly. However, treaty provisions can affect how your business structure is classified—and whether you are deemed to have a permanent establishment (고정사업장) in Korea, which triggers full domestic tax obligations.
Withholding Tax on Payments Abroad
If your Korean entity pays service fees, royalties, or management fees to a foreign parent or non-resident individual, Korea may impose withholding tax at 22% (20% base rate plus 10% local income surtax, as of 2026) on the gross payment, or a lower rate under an applicable tax treaty. Verify the current statutory rate and applicable treaty rate for your home country under the Income Tax Act (소득세법) or Corporate Tax Act (법인세법) at nts.go.kr, as rates and treaty applications require case-by-case confirmation. This is separate from VAT but affects cash flow and must be managed at payment time.
Foreign Bank Account Reporting
If you are a Korean tax resident with foreign financial accounts exceeding certain aggregate thresholds, you have reporting obligations; the specific threshold and applicable law should be confirmed with a tax professional, as the Foreign Exchange Transactions Act (외국환거래법) and related regulations are periodically amended. Non-residents operating through Korean entities have different exposure—consult a tax professional on your specific structure.
Over the years I’ve helped foreign-founded startups navigate the Korean tax system, the question of foreign account reporting is one of the most commonly overlooked obligations among first-time non-resident business owners. It sits in a regulatory gap between NTS jurisdiction and Financial Services Commission (금융위원회) oversight, and the consequences of missing it are disproportionate to how obscure it sounds. If you have accounts abroad exceeding any plausible reporting threshold, ask your 세무사 directly.
Frequently Asked Questions
Do I have to register for Korean VAT if I’m only freelancing part-time?
It depends on two things: your annual turnover and the nature of your service. The KRW 104 million simplified-taxpayer threshold (as of 2026 — verify at nts.go.kr) applies to total revenue, not hours worked. If you are providing taxable services (consulting, design, software, translation) and billing Korean businesses, you need a business registration. VAT exemption (면세) is limited to law-listed categories (basic food, certain medical/education) — most B2B professional services are never exempt regardless of size. Part-time status is not a legal basis for avoiding registration if you cross the threshold.
Can I get a VAT refund if I’m not a Korean resident?
Yes, under specific conditions. Non-resident businesses with Korean VAT registration can claim refunds on input VAT when their output is zero-rated (exports). The process is the same as for residents, but documentation requirements are stricter—particularly proof that services were consumed outside Korea. Non-registered foreign businesses supplying digital services under the simplified registration system have a different, more limited refund path. Consult the NTS English guidance at nts.go.kr/english or a licensed tax agent for your specific structure.
What happens if I file VAT late—will I get audited?
Not automatically. A single late filing with a small amount due triggers a penalty (10% of unpaid tax) and interest—not an audit notice. Repeated late filings, large underpayments, or patterns of amended returns increase your risk profile in the NTS system. Korea’s NTS (국세청) uses data-matching across invoices, bank data, and customs records, so unexplained discrepancies are a bigger audit trigger than late filing alone. If you are consistently late, fix the process—set calendar reminders for the 25th of April, July, October, and January.
Do I need a Korean accountant to handle VAT, or can I use software?
You can file through NTS Hometax yourself if you read Korean and your situation is straightforward. There is no English-language equivalent of a one-click VAT filing tool for Korea. For a single-entity domestic business with clean records, DIY is workable after the first filing. For export refunds, mixed taxable/exempt income, cross-border transactions, or if you are simply not confident in Korean tax navigation, a 세무사 is worth the quarterly fee. The risk of filing errors is real and the documentation to correct them is in Korean.
How do the simplified-taxpayer and payment-exemption thresholds work if my revenue fluctuates?
The threshold is calculated on a calendar year basis (January–December), not rolling 12 months. Register as a general taxpayer before you start invoicing taxable supplies — you cannot retroactively recover input VAT or fix your taxpayer status for months you operated unregistered. Once registered as a general taxpayer, you remain registered even in years your revenue falls below the threshold. Deregistration requires a separate application and has conditions. If your income fluctuates near the threshold, get an accountant’s advice before year-end to plan correctly.
What to Do Next
Your first concrete step: determine whether your business activity is taxable (과세) or exempt (면세) under Korean VAT law. This single determination changes everything downstream—registration requirement, invoice type, refund eligibility. The NTS website (nts.go.kr) has a business type search function (업종코드 조회) that maps your activity to its tax treatment.
If you haven’t yet completed your first-time business registration process, start there—VAT registration is a step inside that larger process, not separate from it.
For ongoing compliance, read our guide on choosing an accountant who handles foreign-owner VAT before you engage anyone. The difference between a 세무사 who handles foreigners regularly and one who doesn’t is significant.
I am not a licensed Korean tax attorney or 세무사. This guide reflects research and documented procedures as of 2026; tax rules change. For entity-specific advice, cross-border income, or treaty claims, consult a licensed professional.
Disclaimer: This post reflects the author’s experience and publicly available information as of 2026. It is general information, not legal, tax, or immigration advice. Rules and rates change — verify current details with the relevant authority (NPS, NTS, MOJ) or a licensed professional before acting.
공급시기 기준과 지급일 기준의 차이를 짚어준 점이 특히 좋네요. 고객이 언제 입금하든 공급월 다음 달 10일까지 세금계산서를 발행해야 한다는 부분은 외국인 창업자들이 가장 많이 놓치는 지점입니다. 실무적으로 정리가 잘 된 글이네요. 잘 읽었습니다.