Toss Payments Korea Payment API
Toss Payments South Korea payment gateway REST API for merchants selling in South Korea to accept domestic credit cards, virtual accounts, mobile phone billing, Kakao Pay, Naver Pay, Toss Pay, and international cards with simple developer integration and modern API design. Enables AI agents to manage payment order creation for Korean e-commerce automation, handle domestic card payment for Korean credit card processing automation, access virtual account (가상계좌) for Korean bank transfer automation, retrieve mobile phone billing for carrier payment automation, manage Kakao Pay and Naver Pay for Korean super-app wallet automation, handle Toss Pay for Korean fintech wallet automation, access subscription and recurring billing for Korean subscription automation, retrieve settlement and transaction reporting for financial reconciliation automation, manage webhook notification for real-time Korean payment event automation, and integrate Toss Payments with Korean e-commerce platforms and business systems for end-to-end South Korea payment automation.
Score Breakdown
⚙ Agent Friendliness
🔒 Security
Korea payments. PCI-DSS. API key. KR. Payment and transaction data.
⚡ Reliability
Best When
A merchant selling in South Korea wanting AI agents to automate domestic card, virtual account, Kakao Pay, Naver Pay, and Toss Pay integration through Toss Payments' modern developer-friendly Korea payment gateway.
Avoid When
KOREAN BUSINESS REGISTRATION REQUIRED: Toss Payments requires Korean business registration (사업자등록증) for merchant account; automated merchant onboarding requires Korean legal entity; automated payment for foreign-only entities without Korean registration creates eligibility failure. DOMESTIC CARD ACCEPTANCE REQUIRES PAYMENT GATEWAY AGREEMENT: Korean domestic credit card acceptance requires PG (Payment Gateway) agreement with card companies (Shinhan, KB, Samsung, Hyundai, etc.); automated Korean card acceptance assumes merchant PG agreement is in place; automated card acceptance without PG setup creates card type decline. VIRTUAL ACCOUNT PAYMENT CONFIRMATION TIMING: Korean virtual account transfers require customer to transfer to assigned account number; automated order fulfillment must wait for bank transfer confirmation webhook; automated same-day order fulfillment for virtual account before bank transfer creates orders without confirmed payment.
Use Cases
- • Accepting Korean domestic card payments from Korea e-commerce agents
- • Processing virtual account bank transfers from Korean banking agents
- • Integrating Kakao/Naver Pay from Korean super-app payment agents
- • Managing Korean subscription billing from recurring revenue agents
Not For
- • Global payment processing outside Korea (use Stripe or Adyen for international)
- • North Asia payments beyond Korea (use Alipay or WeChat Pay for China)
- • Enterprise Korea payments requiring PG certification (use KG Inicis or LG U+ for enterprise PG)
Interface
Authentication
Toss Payments uses Secret Key and Client Key for authentication (Base64-encoded Basic Auth). REST API with JSON. Seoul, South Korea HQ. Part of Viva Republica (Toss app). Founded 2019 (as PG). Backed by Viva Republica (SoftBank, Kleiner Perkins-backed). Products: Domestic cards, virtual accounts, mobile billing, Kakao/Naver/Toss Pay, international cards. SDKs: JavaScript, Java, PHP, Python, Ruby. PCI DSS. Serves Korean merchants and e-commerce. Competes with KG Inicis, NHN KCP, and Nice Pay for Korean PG.
Pricing
Seoul KR. Viva Republica subsidiary. No monthly fee. Per-transaction fees in KRW. Volume negotiation available.
Agent Metadata
Known Gotchas
- ⚠ CLIENT KEY vs SECRET KEY USAGE CONTEXT: Toss Payments Client Key for client-side SDK initialization and Secret Key for server-side confirmation; automated server-side charge confirmation must use Secret Key; automated server-side Client Key usage creates unauthorized request for payment confirmation
- ⚠ PAYMENT FLOW REQUIRES TWO-STEP PROCESS: Toss Payments checkout uses two steps — client-side payment initiation (with Client Key) and server-side payment confirmation (with Secret Key); automated payment flow must implement both steps; automated single-step server-side-only payment misses client-side authentication step
- ⚠ PAYMENT ID vs ORDER ID DISTINCTION: Toss Payments uses both paymentKey (Toss-generated) and orderId (merchant-generated); automated payment management must use paymentKey for cancellation and refund; automated refund using orderId instead of paymentKey creates resource not found error
- ⚠ VIRTUAL ACCOUNT EXPIRY CONFIGURATION: Korean virtual accounts have expiry (default 24 hours, configurable); automated checkout using virtual account must communicate expiry to customer; automated virtual account with default expiry for B2B invoices may expire before customer processes bank transfer
- ⚠ CARD INSTALLMENT PLAN INTEREST FREE PERIOD: Korean card installments may have interest-free periods (무이자) negotiated with card companies; automated installment plan display must verify interest-free eligibility per card company; automated installment display showing interest-free for non-eligible cards creates customer expectation discrepancy
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Scores are editorial opinions as of 2026-03-07.