USTaxPenaltySaver
B2C FinTech SaaS — IRS Penalty Calculator & Resolution Platform
Full product build — research, design, development, deployment
An affordable middle ground
Build a production-grade B2C SaaS platform that replaces $200-500/hr CPA consultations with a $39.99 self-service tool — calculating IRS penalties, generating professional abatement letters, and guiding taxpayers through resolution. Requires encoding complex IRS tax code across 50 states + DC with full bilingual (EN/ES) support.
What we built
We delivered a comprehensive FinTech platform with 31 penalty calculators, 21 PDF letter generators, AI-powered notice scanning, a relief discovery engine, and complete Spanish translation — all running at under £70/year infrastructure cost.
31 penalty calculators
Every major IRS penalty type — Failure-to-File, Failure-to-Pay, Estimated Tax (Form 2210), Accuracy (IRC 6662), Trust Fund Recovery, FBAR, Information Returns, ERC and more — with Zod-validated inputs and CPA-accurate results.
21 PDF letter generators
IRS-ready documents: FTA abatement letters, reasonable-cause letters (11 IRM categories), Form 843 prep sheets, CDP / Form 12153 letters, streamlined-filing packages, TFRP defense and Innocent Spouse analysis — each with service-center lookup, deadlines and phone scripts.
AI notice scanner
OCR pipeline on Google Cloud Vision accepts photos of IRS notices, extracts notice codes, penalty amounts, tax year and deadlines via regex, then routes users to the right calculator with pre-filled values.
Relief discovery engine
Smart eligibility engine across 11 IRS relief programs, surfacing recommendations as “Likely to Qualify”, “Worth Exploring” and “Payment Options” using penalty type, filing status, business ownership, international exposure and hardship indicators.
Interactive denial-flow wizard
Guided step-by-step path for denied relief requests — FTA Denied → Reasonable Cause → Audit Reconsideration → Payment Options — explaining each denial reason and the next available option.
Complete bilingual support (EN/ES)
49 translated pages and 7,368 keys per language with zero missing translations. PDF output generates English (for IRS submission) and Spanish (for user reference) via next-intl.
What makes it production-grade
- 31 IRS penalty calculators with Zod-validated inputs
- 21 professional PDF letter generators (IRS-ready)
- AI notice scanner with OCR pipeline (Google Vision)
- Relief discovery engine across 11 IRS programs
- Full bilingual support (7,368 keys EN/ES)
- CCPA-compliant with SSN-safe handling (last 4 only)
Secure by default
- SSN-safe: only last 4 digits accepted / stored
- US data residency (GCP us-central1)
- Zod schemas + HTML sanitisation on all endpoints
- Firebase Auth with Bearer token enforcement
- Rate limiting (1,000/min, 1M/month)
- HSTS, X-Frame-Options, CSP headers
- CCPA compliant (Know, Delete, Export, Opt-Out)
- Automated npm audit + TruffleHog scanning
The stack underneath
End to end, by one team
- IRS domain research (14 technical guides)
- Product strategy & UX design
- Full-stack development (111 phases)
- Penalty calculation engine (31 calculators)
- PDF generation system (21 templates)
- AI/OCR notice scanning pipeline
- Bilingual i18n implementation
- Security hardening & CCPA compliance
- Production deployment & monitoring
What the client got
- A production SaaS platform matching CPA-level output for penalty calculations and abatement letters
- 80–95% cost reduction vs professional tax consultation ($39.99 vs $200–500+)
- Full US market coverage with state-specific penalty data (50 states + DC)
- Complete Spanish support removing the language barrier for millions of taxpayers
- Step-by-step guided workflows with phone scripts and fill-in-the-blank templates
- Solo-founder-ready infrastructure (under £70/year, auto-scaling, no DevOps needed)
Have a similar challenge?
From complex domain research to production-ready SaaS — we build platforms that replace expensive professional services with intelligent self-service tools.