Taiwan Payment Integration
Framework
IRON LAW: Support At Least 3 Payment Methods in Taiwan
Taiwan consumers expect choice. Credit card alone misses ~40% of potential
buyers. The minimum viable payment mix for Taiwan e-commerce:
1. Credit card (信用卡)
2. ATM/bank transfer (ATM 虛擬帳號)
3. Convenience store payment (超商代碼/超商取貨付款)
Adding LINE Pay and Apple Pay captures another 10-15%.
Taiwan Payment Landscape
| Method | Market Share | User Profile | Settlement Time |
|---|
| Credit/Debit card | ~45% | All ages, higher spending | T+1 to T+7 |
| ATM virtual account | ~15% | Price-sensitive, no credit card | Instant to T+1 |
| Convenience store (超商代碼) | ~10% | Students, cash-preferred | T+1 to T+3 |
| LINE Pay | ~12% | LINE users (95% of Taiwan) | T+1 to T+7 |
| Apple Pay / Google Pay | ~5% | Mobile-first users | T+1 to T+7 |
| 超商取貨付款 (COD at store) | ~8% | Low trust, want to see product | Upon pickup + T+3 |
| JKoPay / 街口 | ~3% | Younger demographic | T+1 |
Payment Service Providers (PSP)
| PSP | Strengths | Pricing | Best For |
|---|
| 綠界 (ECPay) | Most comprehensive (credit card, ATM, CVS, 超取), largest market share | 2.75% credit card, NT$15/ATM txn | General e-commerce, startups |
| 藍新 (NewebPay) | Good API design, modern dashboard | 2.5-2.8% credit card | SaaS, subscription businesses |
| TapPay | Mobile-first, Apple Pay/Google Pay/LINE Pay integration | 2.5-2.8% credit card | Mobile apps, in-app purchases |
| PayNow | Easy setup, no monthly fee | 2.75% credit card | Low-volume, new businesses |
| Stripe | International, excellent API | 3.4% + NT$10 per txn | Cross-border, international focus |
Integration Flow (Standard)
1. Customer clicks "Pay" on your site
2. Your server creates an order → sends to PSP API
3. PSP returns a payment page URL (or token for inline)
4. Customer completes payment on PSP-hosted page
5. PSP sends callback (webhook) to your server with result
6. Your server verifies the callback signature
7. Update order status → show confirmation to customer
Key API Concepts
| Concept | What It Is |
|---|
| MerchantID | Your account identifier with the PSP |
| HashKey / HashIV | Secret keys for signature verification |
| TradeNo | Your order ID (must be unique per transaction) |
| PaymentType | Credit, ATM, CVS, WebATM, etc. |
| Callback URL | Webhook endpoint PSP calls after payment |
| Return URL | Page to redirect customer after payment |
| CheckMacValue | HMAC signature to verify data integrity |
Refund Handling
| Method | Refund Capability | Timing |
|---|
| Credit card | Full or partial refund via API | 1-7 business days |
| ATM | Cannot auto-refund — must wire transfer back | Manual, 3-7 days |
| CVS payment | Cannot auto-refund — must wire transfer back | Manual, 3-7 days |
| LINE Pay | Full refund via API | 1-3 business days |
Security Requirements
| Requirement | What to Do |
|---|
| SSL/TLS | All payment pages must be HTTPS |
| 3D Secure | Enable 3DS 2.0 for credit card fraud reduction |
| PCI DSS | If handling raw card data, need PCI compliance. Using PSP-hosted payment page avoids this. |
| Tokenization | Store payment tokens, never raw card numbers |
| Webhook verification | Always verify CheckMacValue signature before processing callbacks |
| Idempotency | Handle duplicate callbacks gracefully (PSP may retry) |
Output Format
# Payment Integration Plan: {Business}
## Payment Method Selection
| Method | Include? | PSP | Rationale |
|--------|---------|-----|-----------|
| Credit card | Y/N | {provider} | {why} |
| ATM | Y/N | ... | ... |
| CVS | Y/N | ... | ... |
| LINE Pay | Y/N | ... | ... |
## PSP Selection
- Provider: {name}
- Pricing: {rate}
- Rationale: {why this provider}
## Integration Plan
| Phase | Task | Timeline |
|-------|------|----------|
| 1 | Apply for PSP merchant account | 1-2 weeks |
| 2 | Develop payment flow (sandbox) | 1-2 weeks |
| 3 | Implement webhook handler | 1 week |
| 4 | Security review (SSL, signature verification) | 2-3 days |
| 5 | Production testing with real transactions | 1 week |
| 6 | Go-live | 1 day |
## Refund Process
{How each payment method handles refunds}
Gotchas
- PSP application takes time: Merchant account approval can take 1-3 weeks. Apply early. Credit card processing requires additional documentation (company registration, bank account proof).
- ATM and CVS refunds are manual: Unlike credit cards, ATM and convenience store payments cannot be auto-refunded. You need the customer's bank account to wire money back. Build this into your CS process.
- Webhook reliability: PSP callbacks can be delayed or duplicated. Build idempotent handlers and implement a reconciliation job that checks PSP records against your database daily.
- Foreign credit cards: Not all Taiwan PSPs support foreign credit cards well. If you have international customers, test with non-Taiwan cards or use Stripe.
- Recurring payments (subscription): 綠界 and 藍新 support recurring billing, but you need the customer's explicit consent and must handle card expiration/update flows.
References
- For 綠界 API integration guide, see
references/ecpay-api.md - For PCI DSS compliance checklist, see
references/pci-checklist.md
