Dolibarr Hook System Integration:
- Hook into invoice validation and accounting transfer events
- Automatic EU supplier detection and autoliquidation
- Custom fields for VAT processing (EU flag, transaction type)
- Batch processing for multiple invoices
- Workflow triggers for status changes
Available Hooks:
- supplier_invoice_validate: Auto-detect EU suppliers
- supplier_invoice_accountancy_transfer: Create VAT entries
- invoice_validate: Apply EU transaction rules
- invoice_accountancy_transfer: Generate accounting entries
Automation Workflow:
1. User creates EU supplier invoice
2. Hook triggers on validation
3. Auto-detect EU supplier
4. Create VAT due (4452xxx) and deductible (4456xx) entries
5. Entries ready for CA-3 calculations
Custom Fields:
- EU Supplier Flag
- VAT Treatment (autoliquidation vs normal)
- Transaction Type (B2B, B2C, special cases)
- OSS Threshold tracking
- DEB/DES requirement flags
Enhanced Features:
- Automatic VAT processing
- Reduced manual work for EU transactions
- Seamless integration with Dolibarr workflow
- Custom field management
- Batch processing capabilities
Updated estimates: +44 hours for workflow integration
Total project: 456+ hours with full Dolibarr integration
EU Transaction Scenarios:
1️⃣ Incoming EU Invoices (Purchases):
- Supplier invoices HT (no VAT)
- French autoliquidation: 4452xxx (VAT due) + 4456xx (VAT deductible)
- Net effect: zero if fully deductible
- CA-3 impact: Lines 17 (VAT due) + 20/21 (VAT deductible)
2️⃣ Outgoing EU Invoices (Sales):
- Case A (B2B): No French VAT, Lines 05/06 (base HT only)
- Case B (B2C): OSS threshold handling (€10,000)
- Case C (Special): Construction/energy reverse charge
- Invoice text requirements for EU transactions
3️⃣ DEB/DES Integration:
- Link CA-3 lines 05/06 with exchange declarations
- Cross-validation between CA-3 and DEB/DES
- Automatic data import and validation
Enhanced Features:
- EU transaction type detection and classification
- OSS threshold monitoring and alerts
- DEB/DES data integration and validation
- Special case handling (construction, energy)
- Comprehensive EU transaction workflow
Updated estimates: +64 hours for EU transaction handling
Total project: 414+ hours with full EU compliance
Official CA-3 Form Lines:
- Section A: Opérations imposables (A1, A2, B1-B4)
- A1: Base HT of taxable operations
- A2: Special operations (asset sales, self-deliveries)
- B1-B4: Rate breakdowns (20%, 10%, 5.5%, 2.1%) with base + tax
- Section B: TVA due (Line 17)
- Intra-EU acquisitions autoliquidation
- Section C: TVA déductible (Lines 20, 21)
- Line 20: Capital goods VAT
- Line 21: Operating expenses VAT
- Section D: Résultat (Lines 22, 28, 29)
- Line 22: VAT credit to carry forward
- Line 28: Net VAT to pay
- Line 29: VAT credit amount
Enhanced Features:
- Detailed account breakdown for draft declarations
- Drill-down from form lines to individual transactions
- Separate handling of base amounts (HT) and VAT amounts
- Support for all French VAT rates
- Special operations handling (A2 line)
- Export detailed breakdown reports
Updated task estimates: +37 hours for form structure implementation
Added comprehensive bilingual support for all CA-3 form lines
Core Advanced Features:
- Draft system with detailed account breakdowns
- Validation workflow with approval process
- Automatic journal entry generation (445510/445670)
- Complete audit trail and version history
- Multi-entity support for multiple companies
Analytics & Reporting:
- Period comparison tools with variance analysis
- Interactive dashboard with KPIs and trends
- Exception handling for unusual amounts
- Automated alerts and notifications
User Experience:
- Mobile-responsive design
- Document management with attachments
- Email notifications for deadlines
- Keyboard shortcuts and accessibility
Integration & APIs:
- External tax system integration
- Backup/restore functionality
- Webhook support for real-time updates
- API documentation for third-party access
Updated time estimates: 350+ hours total
Added Phase 7 (Advanced Features) with 80+ hours
Enhanced bilingual support for all new features
- Create PLANNING.md with detailed project architecture and phases
- Create TASK.md with 200+ hour development plan broken into 6 phases
- Add French language support (fr_FR/declarationtva.lang)
- Update English translations with CA3-specific terminology
- Define CA3 box structure and PCG account mappings
- Plan bilingual interface for French-speaking users
- Include database schema, testing, and documentation phases
- Add core module structure
- Include admin interface
- Add language support (en_US)
- Include SQL schema
- Add build configuration
- Include documentation and licensing
