eutaxes.app

The Challenge

Cross-border tax compliance in the EU is a maze. A freelancer in the Netherlands invoicing a German client faces different VAT rules than one invoicing in France, and the rules change yearly. Existing tools are either expensive accountant portals or oversimplified calculators that get edge cases wrong. The goal was to build something accurate enough to be useful, but accessible enough that non-accountants can understand it.

My Contribution

Designed and built the country-specific tax rule engine covering VAT obligations, tax residency determination, and cross-border reporting requirements across multiple EU member states. Each rule is versioned and unit-tested against official tax authority documentation.

Built the frontend with React and Next.js, focusing on making complex tax concepts understandable through progressive disclosure, plain-language explanations, and interactive calculators. Used AI to accelerate regulatory research and draft initial rule descriptions, but every rule was manually verified against official sources. The architecture supports annual regulatory updates without code changes.

Key Results

• Rule engine covering VAT and income tax rules for major EU member states
• Interactive calculators used by freelancers for cross-border tax planning
• Tax rules versioned and unit-tested against official regulatory documentation
• AI-accelerated research workflow cutting regulatory update time significantly

Technologies Used