asgard-ai-platform Taiwan E-Invoice System (電子發票)
Framework
IRON LAW: E-Invoice Is Mandatory for Most B2C Businesses
Since 2019, businesses using 統一發票 must issue electronic invoices
through the 財政部電子發票整合服務平台. Paper invoices are being phased
out. Non-compliance triggers penalties and may affect 營業稅 filing.
System Architecture
Your System (POS/ERP/E-commerce)
↓ API / Turnkey
財政部電子發票整合服務平台 (einvoice.nat.gov.tw)
↓
Consumer (via 載具: 手機條碼 / 自然人憑證 / App)
↓
國稅局 (tax reconciliation)
Integration Methods
| Method | How It Works | Best For | Complexity |
|---|---|---|---|
| Turnkey | Install MOF-provided software, batch upload invoices | Traditional businesses, low volume | Medium |
| API (加值服務中心) | Connect via 加值中心 API (e.g., 綠界、藍新) | E-commerce, SaaS, high volume | Low-Medium |
| Direct API | Connect directly to MOF platform | Large enterprises with IT team | High |
| POS integration | POS vendor handles e-invoice natively | Retail, F&B | Low (vendor does it) |
B2B vs B2C Invoice Differences
| Aspect | B2B (營業人對營業人) | B2C (營業人對消費者) |
|---|---|---|
| Buyer info | Buyer's 統編 required | No 統編 (consumer) |
| Format | 三聯式 | 二聯式 |
| Tax display | Tax amount shown separately | Tax included in price |
| Carrier | N/A | 手機條碼, 自然人憑證, or membership carrier |
| Prize eligibility | No | Yes (中獎機制) |
Carrier Types (載具)
| Carrier | Code Format | Use Case |
|---|---|---|
| 手機條碼 | /XXXXXXX (slash + 7 chars) | Most common consumer carrier |
| 自然人憑證 | 2 letters + 14 digits | Government ID-linked |
| 會員載具 (membership) | Defined by business | Loyalty program integration |
| 捐贈碼 | 3-7 digits | Donate invoice to charity |
Implementation Steps
Phase 1: Registration
- Register on 財政部電子發票整合服務平台
- Apply for 加值服務中心 AppID (if using API method)
- Set up certificate and authentication
Phase 2: Development/Integration 4. Choose integration method (Turnkey vs API vs POS) 5. Implement invoice issuance: create, void, void-and-reissue 6. Implement carrier scanning (手機條碼 barcode) 7. Handle 捐贈碼 (donation codes)
Phase 3: Testing 8. Test in sandbox environment 9. Issue test invoices, verify on MOF platform 10. Test void/reissue flows
Phase 4: Go-Live 11. Switch to production environment 12. Monitor daily: match issued invoices vs MOF records 13. Bimonthly: reconcile with 營業稅 filing (401 form)
Common API Flows
Issue Invoice:
POST /invoice → { seller_id, buyer_id (optional), items[], amount, tax, carrier_type, carrier_id }
→ Response: { invoice_number, invoice_date, random_code }
Void Invoice:
POST /invoice/void → { invoice_number, invoice_date, void_reason }
Query Invoice:
GET /invoice/{number} → { status, items, amount, carrier }
Output Format
# E-Invoice Implementation Plan: {Business}
## Current State
- Business type: B2B / B2C / Both
- Current invoicing: Paper / Partial e-invoice / None
- Transaction volume: {N}/month
## Integration Method
- Method: {Turnkey / API / POS integration}
- Provider: {加值中心 name, if applicable}
- Rationale: {why this method}
## Implementation Checklist
- [ ] MOF platform registration
- [ ] AppID obtained
- [ ] Integration developed
- [ ] Sandbox testing passed
- [ ] Carrier scanning implemented
- [ ] Donation code support
- [ ] Production go-live
- [ ] Reconciliation process documented
## Timeline
| Phase | Duration | Milestone |
|-------|----------|-----------|
| Registration | 1-2 weeks | AppID obtained |
| Development | 2-4 weeks | Integration complete |
| Testing | 1-2 weeks | Sandbox verified |
| Go-live | 1 day | First production invoice |
Gotchas
- Invoice number format is assigned by MOF: You don't generate invoice numbers. The MOF assigns number ranges (字軌) that you request in advance. Run out of numbers = can't issue invoices. Request well ahead of time.
- Void window is limited: Invoices can be voided within the same bimonthly period. After the period closes, voiding requires a more complex process (折讓).
- 手機條碼 scanning: The barcode is a slash + 7 characters. Many POS scanners need configuration to read this format correctly. Test with real 手機條碼 barcodes.
- Prize drawing (中獎): B2C e-invoices are automatically entered into the government lottery (統一發票兌獎). Your system must support winner notification if the invoice was stored in a membership carrier.
- Reconciliation is critical: The MOF platform is the source of truth. If your system's invoice records don't match the platform, your 營業稅 filing will have discrepancies. Reconcile daily.
References
- For 加值服務中心 API documentation, see
references/einvoice-api.md - For 營業稅 filing reconciliation, see the tw-tax-basics skill