Plataforma de otimização fiscal para contribuintes portugueses.
fiscalpt.com · Guias · Blog
FiscalPT analyzes Portuguese household tax data and computes the optimal filing strategy — joint vs separate, IRS Jovem, NHR, deduction optimization — with concrete savings recommendations in euros.
Upload your AT tax documents (XML Modelo 3 or comprovativo PDF), answer a few follow-up questions, and get an instant, detailed analysis comparing every filing scenario.
- Deterministic tax engine — pure TypeScript, no LLMs in the calculation pipeline. Every result is reproducible and verifiable.
- Joint vs separate filing — side-by-side comparison with quociente conjugal.
- IRS Jovem — Art. 12-F CIRS, both pre-2025 and 2025+ rules.
- NHR regime — Art. 72, 20% flat rate on qualifying income.
- Cat A/B/E/F/G/H — category-specific rules, simplified regime coefficients, englobamento simulation.
- Social Security — Cat A employee and Cat B independent worker computation.
- Deductions — dependents, health, education, housing, PPR, and more.
- AT document parsing — XML Modelo 3 (primary) and comprovativo PDF (fallback), with automatic data extraction.
- 1060+ automated tests — property-based fuzz testing, AT liquidação cross-validation, comprehensive edge case coverage.
- Privacy-first — all processing happens in the browser. Zero servers, zero data collection.
- 2024 (Lei 33/2024)
- 2025 (OE 2025)
| Layer | Technology |
|---|---|
| Framework | Next.js · React 19 · TypeScript |
| Styling | Tailwind CSS · base-ui components |
| Tax Engine | Pure TypeScript — deterministic, ~96% code coverage |
| Testing | Vitest · Playwright · fast-check (property-based) |
| Task Runner | Just |
We welcome contributions! See CONTRIBUTING.md for guidelines on code quality, TDD workflow, and commit conventions.
The tax engine is the core of the project — if you spot a calculation that doesn't match the official AT output, please open an issue.
git clone https://github.com/ruifm/fiscalpt.git
cd fiscalpt
npm install
just check # types → lint → format → testsSee CONTRIBUTING.md for full development workflow details.
- Issues — bug reports and feature requests
- Discussions — questions and general discussion
- Security Policy — responsible disclosure
- Careers — open-source contribution opportunities
GNU Affero General Public License v3.0 — free to use, modify, and distribute. If you run a modified version as a service, you must share your source code.