FinTech / Tax Compliance (USA)
USTaxPenaltySaver
B2C FinTech SaaS — IRS Penalty Calculator & Resolution Platform
Full product build — research, design, development, deployment
The brief
Challenge → solution
01 · The challenge
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.
Replace $200-500/hr consultations at $39.99
Professional abatement letters
IRS tax code across 50 states + DC
Full bilingual (EN/ES) support
02 · The solution
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.
31 penalty calculators
21 PDF letter generators
AI notice scanner
Relief discovery engine
Interactive denial-flow wizard
Complete bilingual support (EN/ES)
Option
Cost
Accessibility
Completeness
CPA / Tax Attorney
$200–500+/hr
Appointments required
High (if affordable)
IRS.gov
Free
Poor UX
Partial
Free calculators
Free
Limited
Very low
USTaxPenaltySaver
$39.99
Self-service, bilingual
Full
By the numbers
live in production · ustaxpenaltysaver.comThe results
0
Calculators
IRS penalty types covered
0
PDF Generators
Professional letter templates
0,368
i18n Keys
Full EN/ES translation
<£0/yr
Infra Cost
Auto-scaling Cloud Run
0-95%
Cost Savings
vs CPA consultation
Highlights
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)
Security & compliance
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
Technology
The stack underneath
Frontend
Next.js 14 (App Router)
Backend
Next.js API Routes + Cloud Run
Database
Firebase / Firestore
AI / OCR
Google Cloud Vision API
PDF Generation
jsPDF (server-side)
i18n
next-intl (EN/ES)
Hosting
Google Cloud Run (us-central1)
Auth
Firebase Authentication
Testing
Vitest
Services delivered
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
Your build next
Have a similar challenge?
From complex domain research to production-ready SaaS — intelligent self-service tools that replace expensive professional services.