Split View: 한국 사업자 세금 완전 정복: 부가세·현금영수증·세금환급 실전 가이드

Korea Business Tax Complete Guide: VAT, Cash Receipts, and Tax Refunds

Table of Contents

1. Business Registration and Tax Basics
2. Value-Added Tax (VAT) Complete Guide
3. Cash Receipt Complete Guide
4. Reducing VAT Through Input Tax Deductions
5. How to Claim VAT Refunds
6. Correcting Tax Invoice Mistakes
7. Quiz

1. Business Registration and Tax Basics

1.1 Why Business Registration Matters

The very first step when starting a business in Korea is business registration (사업자 등록). Without it, you cannot issue tax invoices, claim input tax deductions, or properly account for business expenses. You should register before you start operations or within 20 days of commencing business, either at your local tax office or online through Hometax (hometax.go.kr).

Documents required for business registration include:

• Business registration application form
• Copy of the lease agreement (if the premises are rented)
• Copy of your ID
• For corporations: corporate registry extract and articles of incorporation

1.2 Sole Proprietor vs. Corporation — Tax Differences

The tax structure differs significantly depending on your business form. Which is more advantageous depends on your revenue scale and growth plans.

Sole proprietors have their business income added to their personal income and pay comprehensive income tax (종합소득세). The rate is progressive, ranging from 6% to 45%, so the tax burden rises sharply as income grows.

Corporations pay corporate tax (법인세), which is designed with lower rates than personal income tax. Once income exceeds a certain threshold, converting to a corporation is worth considering.

Corporations can treat the representative's salary as an expense, making it possible to reduce the overall tax burden by distributing income between the company and the representative's salary. However, incorporation involves complex setup procedures and higher accounting and tax management costs.

1.3 General Taxable vs. Tax-Exempt vs. Simplified Taxable Businesses

Businesses in Korea are classified into three types based on VAT obligations.

General Taxable Businesses (일반과세자) These businesses charge and remit VAT at 10% regardless of revenue. They have the right to issue tax invoices and can claim full input tax deductions. Most manufacturers, wholesalers, retailers, and service providers fall into this category.

Tax-Exempt Businesses (면세사업자) These businesses supply goods or services exempt from VAT — such as medical care, education, financial services, books, and agricultural produce. They do not collect VAT and cannot claim input tax deductions either. Instead of tax invoices, they issue regular invoices (계산서).

Simplified Taxable Businesses (간이과세자) This is a simplified tax regime for small individual business owners with annual revenue under KRW 104 million. Tax invoices cannot be issued and input tax deductions are limited, but tax calculation and payment are simpler.

Key features of simplified taxable businesses:

• VAT is calculated using an industry-specific value-added ratio (e.g., restaurants 15%, retail 15%, services 30%)
• Businesses with annual revenue under KRW 48 million are exempt from VAT payment
• They generally cannot issue tax invoices, making it harder for their customers to claim input tax deductions
• Businesses with annual revenue between KRW 48M and KRW 104M can issue tax invoices but remain under simplified rates
• Once annual revenue exceeds KRW 104 million, automatic conversion to general taxable status occurs

Even if you start as a simplified taxable business, if your main customers are corporations or your business has high input costs, switching to general taxable status may be more beneficial.

1.4 Business Registration Number and Tax Invoice Eligibility

Once registration is complete, you receive a business registration number (사업자등록번호) — a 10-digit number used for all tax filings and tax invoice issuance.

To issue tax invoices, you must be registered as a general taxable business. Electronic tax invoices (전자세금계산서) can be issued through Hometax using an accredited or joint certificate for authentication.

2. Value-Added Tax (VAT) Complete Guide

2.1 The Core Structure of VAT

VAT is ultimately borne by the final consumer, but businesses collect it and remit it to the government. The core formula is:

Tax Payable (or Refundable) = Output Tax - Input Tax

• Output tax: VAT collected when selling goods or services (sales amount × 10%)
• Input tax: VAT paid when purchasing goods or services (purchase amount × 10%)
• If output tax exceeds input tax → pay the difference
• If input tax exceeds output tax → receive a refund

For example, if in one quarter your sales were KRW 50 million (VAT KRW 5 million) and purchases were KRW 30 million (VAT KRW 3 million), the tax payable is KRW 5 million - KRW 3 million = KRW 2 million.

2.2 VAT Filing Periods and Payment Schedule

VAT filing and payment deadlines vary by business type. Missing a deadline incurs surcharges, so mark these dates in your calendar.

Corporations (4 filings per year)

Individual General Taxable Businesses (2 filings per year)

Individual businesses are not required to file preliminary returns. Instead, the National Tax Service issues a preliminary notice for 50% of the previous year's VAT. If this notice amount is under KRW 500,000, no notice is issued.

Simplified Taxable Businesses (1 filing per year)

2.3 Tax Invoice Obligations and Deadlines

General taxable businesses must issue a tax invoice when supplying goods or services.

• Issuance deadline: By the 10th of the month following the month of supply
• Example: Supply on March 15 → invoice must be issued by April 10
• Monthly consolidated invoices are also allowed: issue once by the 10th of the following month

Mandatory Electronic Tax Invoice Issuers

All corporations are required to issue electronic tax invoices. Among individual businesses, those whose total supply amount at each business location exceeded KRW 80 million in the previous year must also issue electronic tax invoices.

Failing to issue electronic tax invoices on time results in the following surcharges:

• Non-issuance surcharge: 2% of the supply value
• Late issuance surcharge: 1% of the supply value (from the day after the deadline to the final filing deadline)
• Non-transmission surcharge: 0.5% of the supply value (for issuing but failing to transmit to the NTS)

2.4 How to File VAT on Hometax

Electronic filing is available on Hometax (hometax.go.kr).

1. Log into Hometax (using a joint certificate or simple authentication)
2. Click "Filing/Payment" in the top menu
3. Select "Value-Added Tax"
4. Choose the appropriate return type (general or simplified)
5. Enter sales and purchase data (electronic tax invoices can be imported automatically)
6. Complete and submit the return
7. If there is tax payable, proceed with payment

3. Cash Receipt Complete Guide

3.1 What Is a Cash Receipt?

A cash receipt (현금영수증) is a receipt issued when a consumer pays cash for goods or services. The business transmits the transaction details to the National Tax Service (NTS), and the consumer receives a record. Unlike credit card terminals, the cash receipt system was introduced to bring cash transactions into the formal tax system.

From the consumer's perspective, cash receipts provide an income deduction (30% for wage earners, up to KRW 3 million). For businesses, they serve as purchase evidence when filing corporate or income tax.

3.2 Obligatory Issuance Industries and Minimum Amount

Businesses in NTS-designated mandatory cash receipt issuance industries (현금영수증 의무발행업종) must issue a cash receipt for transactions of KRW 100,000 or more per transaction, even if the consumer does not request one.

Key examples of mandatory industries include:

• Law firms, accounting firms, tax advisory firms, legal scriveners
• Hospitals, dental clinics, oriental medicine clinics, veterinary clinics
• Cram schools and tutoring academies
• Restaurants (including bars)
• Accommodation businesses
• Golf courses and sports facilities
• Wedding venues and funeral homes
• Real estate agencies
• Auto repair shops

Even businesses not in a mandatory industry must issue a cash receipt upon consumer request, with no minimum amount threshold (KRW 1 or more).

3.3 Methods of Issuing Cash Receipts

Cash receipts can be issued in several ways.

Method 1: Direct Issuance via Hometax

1. Go to hometax.go.kr and log in
2. Click "Electronic (Tax) Invoice / Cash Receipt / Credit Card" in the top menu
3. Select "Cash Receipt" → "Issue"
4. Enter transaction details (date of supply, amount, consumer's mobile number or card number)
5. Issuance complete

Method 2: Phone Issuance via ARS 126

Call ARS 126 within 5 days of the cash transaction and follow the prompts to issue a receipt. After authenticating as a business, enter the transaction amount and consumer information. This is useful for small businesses without a terminal.

Method 3: POS/Card Terminal Integration

Most POS systems and card payment terminals have a built-in cash receipt function. When the consumer provides their mobile number or cash receipt card, the system automatically transmits the data to the NTS. This is the most convenient method with the fewest errors.

Method 4: Mobile Payment Platform Integration

When payments are made through platforms like KakaoPay, NaverPay, or TossPay, the platform automatically issues a cash receipt. No separate action is needed on the part of the business.

3.4 Penalties for Not Issuing Cash Receipts

Failing to issue a cash receipt carries serious consequences.

• Fine: 20% of the transaction amount not covered by a cash receipt (for mandatory industries)
• Whistleblower reward: Consumers who report non-issuance receive 20% of the unreported amount (up to KRW 500,000), giving consumers a strong incentive to report violations
• Increased likelihood of being selected for a tax audit

Refusing to issue a cash receipt or issuing one with an incorrect amount is subject to the same penalties.

3.5 Claiming Input Tax Deductions from Cash Receipts

When a business pays cash for purchases and receives a cash receipt, it can claim an input tax deduction just like with a credit card receipt.

The following conditions must be met:

• The expense must be business-related
• It must not fall under non-deductible categories (entertainment expenses, non-business passenger vehicles, etc.)
• The cash receipt must be issued with the business registration number (not as a consumer receipt)

Receipts collected and viewable on Hometax are automatically reflected as input tax data when filing your VAT return.

4. Reducing VAT Through Input Tax Deductions

4.1 How Input Tax Deductions Work

Input tax deductions allow you to subtract VAT paid on business purchases and services from the VAT you owe. This is the cornerstone of VAT tax planning.

For example, if you spent KRW 20 million on interior renovation (VAT KRW 2 million) and your output tax is KRW 5 million, your tax payable becomes KRW 5 million - KRW 2 million = KRW 3 million.

To claim the deduction, you must hold at least one of the following qualifying documents:

• Tax invoice (electronic or paper)
• Credit card receipt (business-purpose)
• Cash receipt (business-purpose)

If you only have a regular receipt without a tax invoice, the deduction cannot be claimed. Making it a habit to collect qualifying documents for every expense is critical.

4.2 Key Deductible Input Tax Items

Raw Materials and Merchandise Purchases VAT paid on raw materials, components, or goods for resale that are directly used in your business is fully deductible.

Office Supplies and Consumables VAT on copy paper, toner, stationery, cleaning supplies, and other office consumables used in your business operations is deductible.

Outsourcing and Professional Services VAT on service fees paid to freelancers or third-party vendors is deductible when you receive a tax invoice. This also applies to payments of a labor-like nature as long as a tax invoice is obtained.

Business Premises Rent VAT on rent for offices, warehouses, stores, or other business premises is deductible. If the landlord is a general taxable business, be sure to receive a tax invoice.

Advertising and Marketing Expenses Tax invoices for online advertising (Google Ads, Naver Ads, etc.), offline marketing materials, and social media marketing agency fees are all deductible. For Google Ads used through a domestic account, tax invoices can be issued.

Business Vehicle Fuel Costs Not all vehicles are eligible.

• Deductible: Trucks, vans with 9 or more seats, light vehicles (engine displacement 1,000cc or less), motorcycles
• Not deductible: General passenger vehicles (displacement over 1,000cc, fewer than 9 seats)

Fuel, repair, and insurance costs for non-business-use passenger vehicles are not deductible. However, vehicles rented for business purposes through a rental company are deductible.

IT Equipment and Software VAT on business-use computers, servers, printers, and other IT equipment, software purchases, and cloud service fees (AWS, Google Cloud, etc.) is deductible when supported by a tax invoice.

Employee Training and Education Costs for employee skills development training, seminar attendance fees, and professional certification costs are also deductible.

4.3 Non-Deductible Input Tax Items

The following are not deductible even if supported by a tax invoice.

Entertainment Expenses Business meals for clients, gifts, golf entertainment, and similar entertainment expenses are not deductible. However, staff dinners for internal purposes or expenses treated as welfare or meeting costs may be deductible.

Non-Business Passenger Vehicles Purchase costs, fuel, insurance, and repair expenses for passenger vehicles (over 1,000cc displacement, fewer than 9 seats) used for personal purposes are not deductible.

Tax-Exempt Business Expenses Input tax related to the supply of tax-exempt goods or services is not deductible.

Land-Related Costs Costs related to land development, grading, or acquisition are not deductible.

Non-Business Expenditures VAT paid on goods or services used for personal purposes cannot be claimed.

4.4 Claiming Deductions via Credit Cards and Cash Receipts

Even without a tax invoice, you can claim input tax deductions by using a business-purpose credit card or obtaining a cash receipt.

Keep in mind this method has limitations:

• Purchases from simplified taxable businesses: not deductible
• Tax-exempt goods and services: not deductible
• Entertainment expenses: not deductible

By registering a business credit card on Hometax, usage data is automatically collected and made available as input data when filing your VAT return. The registration path is: Hometax → Inquiry/Issue → Business Credit Card.

5. How to Claim VAT Refunds

5.1 When Refunds Occur

A VAT refund arises when your input tax exceeds your output tax. This typically happens in the following situations.

New Business or Capital Investment When starting a business or making large capital investments, purchases are high and sales are low, naturally creating a refund position. This is common in construction and manufacturing.

Export Businesses Exports are subject to a zero rate (0%). This means output tax is zero, but VAT paid on domestically purchased raw materials and components remains deductible — resulting in a refund.

Sudden Revenue Decline An unexpected sharp drop in sales can cause output tax to fall below input tax, also generating a refund.

5.2 Regular Refund vs. Early Refund

Regular Refund The standard refund after a VAT return is filed. The refund is received within 30 days of the filing deadline.

Early Refund If any of the following conditions apply, you can receive a refund within 15 days of filing:

• Capital equipment investment
• Export activity
• New business startup
• Supply to the national or local government

Early refunds can also be requested during preliminary filing periods, which is very helpful for businesses with cash flow needs. To apply, check the "Early Refund Application" box on the VAT return.

5.3 Refund Application Process

Completing a VAT return on Hometax automatically triggers the refund process. No separate documents need to be submitted, but the NTS may request supporting documents during its review.

To check your refund status: Hometax → Inquiry/Issue → Tax Refund → Refund Amount Inquiry. Refunds are deposited only to bank accounts held in the business's name, so make sure the account is registered in advance.

5.4 What to Do When a Refund Is Delayed

If the legal deadline (30 days for regular, 15 days for early) passes without receiving your refund, contact the NTS directly.

• NTS Call Center: 126 (weekdays 9 AM – 6 PM)
• Hometax → Civil Service / Consultation → Tax Refund Delay Inquiry
• Visit or call your local tax office

If the delay exceeds the statutory deadline without justification, you may be entitled to additional refund interest on top of the principal amount.

5.5 Common Reasons for Refund Rejection

Key reasons why refund applications are rejected or reduced during NTS review:

• Fictitious or fabricated tax invoices: Tax invoices received without an actual underlying transaction
• Non-deductible items included: Entertainment expenses or non-business vehicle costs claimed as deductible
• Mandatory field errors on tax invoices: Incorrect supplier registration number, amounts, etc.
• Invoices from unregistered or closed businesses: Tax invoices from businesses that have closed or were never properly registered
• Non-business expenditures: Expenses judged to be mixed personal and business use

If a refund is rejected, confirm the reason and consider filing an objection (within 90 days) or a Tax Tribunal petition (within 90 days).

6. Correcting Tax Invoice Mistakes

6.1 When a Corrected Tax Invoice Is Required

When a previously issued tax invoice contains errors, you must issue a corrected tax invoice (수정세금계산서). This is not simply re-issuing an invoice, but rather canceling the original (with a negative amount) or adjusting the difference.

Main situations requiring correction:

• Supply value or tax amount error: Incorrect amounts entered
• Return or refund: The buyer returns goods
• Contract cancellation: The transaction itself is canceled
• Mandatory field errors: Incorrect business registration number, address, etc.
• Discounts or allowances: A discount applied after the original issuance

The deadline for issuing a corrected tax invoice varies by reason. Errors in mandatory fields can be corrected within one year from the day after the final filing deadline.

6.2 Surcharges for Late or Missing Tax Invoices

Failing to issue a tax invoice on time results in surcharges.

For the supplier (issuer)

• Non-issuance: 2% of supply value
• Late issuance: 1% of supply value

For the recipient

• Failure to obtain a tax invoice: Input tax not allowed + 0.5% surcharge on the supply value not covered

Since surcharges are paid on top of the underlying tax, careful management of tax invoice issuance and receipt is critical.

6.3 How to Look Up Received Tax Invoices on Hometax

You can easily check electronic tax invoices you have received on Hometax.

1. Log into Hometax
2. Click "Inquiry/Issue" in the top menu
3. Select "Electronic Tax Invoice" → "Received List Inquiry"
4. Set the inquiry period and search
5. View amounts, supplier information, and issuance dates for each item

For paper tax invoices received outside the electronic system, you must enter them manually. When filing a VAT return, list them in the "Tax Invoice Summary Table" aggregated by supplier.

Because the NTS automatically collects incoming electronic tax invoices, using the "Import Purchase Data" function when filing prevents omissions.

6.4 Using a Tax Accountant

When your business reaches a certain scale or tax matters become complex, hiring a licensed tax accountant (세무사) often saves money in the long run. Tax accountants can assist with tax planning, bookkeeping, return filing, and handling tax audits.

Bookkeeping fees typically range from KRW 100,000 to KRW 300,000 per month depending on revenue and transaction volume — a cost that can easily be offset by avoiding missed deductions and surcharges.

7. Quiz: Check Your Understanding

Conclusion: Key Tax Compliance Checklist

As a business owner in Korea, regularly review the following:

• Monthly: Confirm tax invoice issuance and receipt, organize business credit card records
• Quarterly: Check preliminary filing deadlines and run interim calculations
• Semi-annually: File and pay VAT (individual businesses), finalize input tax deduction items
• Annually: Prepare for comprehensive income tax filing, reassess simplified taxable status

Taxes cannot be avoided, but once you understand the rules, there is significant room to reduce them legally. Making a habit of collecting qualifying documents for every expense, and marking filing deadlines on your calendar in advance, are the simplest ways to avoid unnecessary surcharges.