Korea Qualified Evidence Rules 2026: VAT Invoices and Expense Deductions for Foreign Companies

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Why Qualified Evidence Matters After Incorporation

Many foreign founders focus intensely on Korean company formation, foreign investment notification, paid-in capital, and corporate bank account opening. Those steps are important, but the first real tax risk often appears after the company starts spending money. In Korea, a company does not protect its corporate tax deduction merely by having a contract, a PDF invoice, or a bank transfer record. For many domestic business expenses, the company also needs legally acceptable supporting evidence.

This is often described in English as Korea’s qualified evidence or qualified documentary evidence rule. In Korean practice, accountants are usually looking for tax invoices, credit card sales slips, cash receipts, or other recognized documents that can support both corporate income tax deductibility and VAT input tax credit treatment. If the evidence is missing, the expense may still have been commercially real, but the company can face non-deductibility, VAT credit denial, additional tax, penalties, or uncomfortable questions during a National Tax Service review.

The rule is especially important in 2026 because Korea’s tax administration is highly digital. Electronic VAT invoices are mandatory for suppliers of goods and services in Korea, according to current international tax summaries, and the National Tax Service continues to rely heavily on Hometax data, card transaction data, and electronic filings. For a foreign-owned company, this means expense discipline should be built from day one, not reconstructed at year-end.

What Counts as Qualified Evidence in Korea

Korean tax practice generally treats the following as the core categories of qualified evidence for ordinary business spending:

A commercial invoice from an overseas vendor may be useful, but it is not always a substitute for Korean qualified evidence where Korean VAT or domestic expense rules apply. Likewise, a bank transfer alone proves that money moved; it does not necessarily prove that the company received a deductible business service from a properly documented supplier.

Foreign founders should also distinguish between corporate evidence and personal convenience. A restaurant receipt paid with a founder’s personal card may be explainable, but repeated personal-card spending creates accounting friction. A corporate credit card, corporate bank transfer, or tax invoice issued to the company’s correct business registration number is much cleaner.

VAT Invoices vs. Card Receipts vs. Cash Receipts

Electronic VAT invoices

A Korean electronic tax invoice is normally the strongest document for B2B taxable purchases. It should show the supplier, buyer, business registration numbers, supply value, VAT, issue date, and transaction details. For a VAT-registered Korean company buying office services, software implementation, consulting, marketing, logistics, or equipment from another Korean business, the safest workflow is usually to request a tax invoice issued to the company’s Korean business registration number.

Timing matters. If the tax invoice is issued late, issued to the wrong entity, or later amended, the company may lose a VAT credit or need correction filings. Foreign headquarters should not assume that the Korean subsidiary can simply book expenses based on group purchase orders.

Credit card sales slips

A corporate card receipt can be qualified evidence if it is issued by a properly registered merchant and contains the required transaction data. In practice, corporate cards are very useful for travel, meals, subscriptions, office supplies, and smaller recurring expenses. But the finance team should still keep purpose notes, attendee lists for business meals, project references, and internal approvals where appropriate.

The biggest mistake is treating card data as a complete explanation. The NTS may see that a card transaction occurred, but your accountant still needs to classify the business purpose, deductible portion, VAT treatment, and supporting context.

Cash receipts

Cash receipts are not only for physical cash. In Korea, they can also be relevant when payments are made through bank transfer or other methods where no tax invoice or card slip is available. A cash receipt issued to the company’s business registration number can prevent an otherwise real expense from becoming poorly documented.

Foreign managers often miss this because their home jurisdiction may treat a bank transfer and vendor invoice as enough. In Korea, the practical question is: what will appear in the tax authority’s recognized evidence system?

Common Startup Expenses That Need Extra Care

Incorporation and professional fees

Legal fees, accounting fees, translation, notarization, apostille support, and company registration services should be documented with proper invoices. If the foreign parent paid some pre-incorporation costs, the Korean company should review whether those amounts can be reimbursed, capitalized, or treated as parent-level costs. The answer depends on timing, payer, contract party, and documentary trail.

Office lease and key money

Lease deposits, monthly rent, maintenance charges, and fit-out expenses require careful classification. The lease should identify the correct legal entity. Rent invoices or tax invoices should be issued correctly. Key money is not the same as rent expense; it is typically treated as a deposit or asset until returned or adjusted.

Software and cross-border subscriptions

SaaS subscriptions create frequent confusion. If the vendor is overseas, Korean VAT, reverse-charge concepts, withholding tax, and treaty analysis may need review depending on the nature of the payment. If the vendor is Korean, the company should usually seek a tax invoice or card receipt. Using a founder’s personal overseas card for Korean business software is convenient but creates avoidable evidence and reimbursement problems.

Marketing, influencers, and freelancers

Payments to individuals may require withholding tax reporting. Payments to agencies may require tax invoices. Influencer campaigns can be particularly messy because the recipient may be an individual, sole proprietor, agency, or foreign person. The company should identify the counterparty before payment, not after the campaign ends.

Travel and meals

Travel and entertainment expenses are deductible only when they have a business purpose and proper evidence. Keep itineraries, meeting notes, attendee names, and event details. For meals, a corporate card slip may prove payment, but it does not automatically prove that the expense was not personal.

How Foreign-Owned Companies Should Set Up Internal Controls

A foreign-invested company in Korea should create a simple expense policy before the first month-end close. It does not need to be complicated. It does need to be followed.

Recommended controls include:

• Use the Korean company name and business registration number on vendor records.
• Require electronic tax invoices for Korean B2B taxable purchases unless a card slip or cash receipt is more appropriate.
• Use corporate cards for recurring small expenses and prohibit routine personal-card spending.
• Set a deadline for employees to submit receipts and business purpose notes.
• Review withholding tax before paying individuals, freelancers, instructors, influencers, or directors.
• Maintain a vendor master file with business registration number, bank account, contract, and invoice contact.
• Reconcile Hometax invoice data, card data, and bank statements every month.

The goal is not bureaucracy. The goal is to avoid the painful year-end situation where the company has a bank statement full of payments but cannot prove them in the format Korean tax practice expects.

Mistakes That Trigger Tax Friction

Paying first and asking for evidence later

Some suppliers can issue corrected documents. Others cannot. If the payment structure was wrong from the beginning, fixing it later may require cancellation invoices, revised tax invoices, or reclassification. This consumes time and can delay VAT filings.

Using the parent company as the contracting party

If the parent company signs the vendor agreement but the Korean subsidiary books the expense, the tax position becomes weaker. Intercompany recharge may be possible, but it should be planned with service agreements, transfer pricing support, and proper invoices.

Ignoring VAT input credit conditions

An expense can be commercially real but still fail for VAT credit purposes. For example, the invoice may be issued to the wrong registration number, the expense may relate to non-creditable items, or the company may miss the filing period. The accounting team should review VAT treatment monthly, not only at the annual corporate tax return stage.

Treating all overseas invoices the same

Payments to foreign vendors can raise separate issues: withholding tax, permanent establishment risk, customs value, import VAT, and transfer pricing. A simple overseas PDF invoice may not answer those questions. For recurring or high-value payments, get advice before the payment flow becomes routine.

Practical Checklist for 2026

Use this checklist when setting up a Korean company or cleaning up the first quarter of operations:

1. Confirm the Korean company’s business registration number and use it consistently with vendors.
2. Set up Hometax access, digital certificate access, and accounting firm access early.
3. Open a corporate bank account and avoid founder personal accounts for company expenses.
4. Apply for corporate cards where possible.
5. Prepare a bilingual vendor onboarding form for Korean and foreign suppliers.
6. Decide when to require tax invoices, card slips, cash receipts, import declarations, or withholding filings.
7. Create monthly closing procedures for invoices, receipts, bank statements, and VAT review.
8. Train headquarters finance staff that Korean evidence rules are not the same as general invoice storage.
9. Review related-party charges separately for transfer pricing and documentation.
10. Ask your accountant to flag missing qualified evidence before the VAT filing deadline.

FAQ

Is a bank transfer enough to deduct an expense in Korea?

Usually, no. A bank transfer helps prove payment, but Korean tax practice often expects qualified evidence such as a tax invoice, card slip, or cash receipt. The right document depends on the counterparty and transaction type.

Can a foreign founder pay expenses personally and get reimbursed?

Occasional reimbursement may be possible if the business purpose and supporting documents are clear. However, repeated personal payments create avoidable tax and accounting risk. The company should move to corporate payment methods as soon as possible.

Do overseas vendor invoices need Korean VAT invoices?

Not always. Overseas vendor payments follow a different analysis. The company may need to consider withholding tax, import VAT, reverse-charge concepts, or treaty documents. The correct treatment depends on whether the payment is for goods, services, royalties, software, cloud services, or intercompany support.

What should we do if a supplier issued the invoice to the wrong company name?

Ask for correction promptly. If the tax invoice, card receipt, or cash receipt identifies the wrong buyer, VAT credit and expense support may be weakened. Corrections are easier before the filing deadline.

When should we involve a Korean accountant?

Before operations begin. A short setup session can prevent months of cleanup. For foreign-owned companies, accounting setup should be part of company formation, alongside FDI notification, banking, payroll, and corporate registration.

Korea rewards clean documentation. If your company builds the right evidence workflow from the start, tax filings become calmer, VAT credits are easier to defend, and management can focus on growth instead of receipt reconstruction.

📩 Contact us at sma@saemunan.com