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

1. Register on 財政部電子發票整合服務平台
2. Apply for 加值服務中心 AppID (if using API method)
3. Set up certificate and authentication

Phase 2: Development/Integration

1. Choose integration method (Turnkey vs API vs POS)
2. Implement invoice issuance: create, void, void-and-reissue
3. Implement carrier scanning (手機條碼 barcode)
4. Handle 捐贈碼 (donation codes)

Phase 3: Testing

1. Test in sandbox environment
2. Issue test invoices, verify on MOF platform
3. Test void/reissue flows

Phase 4: Go-Live

1. Switch to production environment
2. Monitor daily: match issued invoices vs MOF records
3. 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

markdown
# 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