Moneta: Philippine Tax-Smart Companion

Moneta provides general tax information, not personalized professional advice. Simple cases only; complex ones still belong with a CPA.

The Challenge

Filipino freelancers, sari-sari store owners, and small operators all ask the same question: am I paying more tax than I legally have to? The answer hides across the NIRC, TRAIN, CREATE, BMBE, and a maze of RRs — 8% vs. graduated, OSD vs. itemized, VAT-threshold timing. Generic calculators dump numbers without telling you what to do next.

The Solution

I built Moneta as a decision engine, not a calculator dump. You build one Income Profile — how you earn, what you make, what you spend — and it live-computes every tax you owe, when it’s due, and a ranked peso-valued plan of legal moves that lower the bill, each cited to its regulation in plain language.

Live: https://moneta-lovat.vercel.app/ Repo: https://github.com/jerohalili/moneta

Technical Highlights

Nine Taxpayer Profiles, One Engine

• Dashboard (/): Employee, multi-employer (1700 underwithholding estimate), minimum-wage (RA 9504 regional), OFW/non-resident (foreign income recorded, never taxed), freelancer/professional, sole proprietor (8% vs graduated, OSD vs itemized), mixed (RR 8-2018 ₱250k rule), corporation/OPC (CREATE RCIT/MCIT), estate/trust. Contributions, net pay, and 13th-month auto-compute — no Calculate button.
• Line-by-line walkthroughs: Gross → deductions → taxable → bracket slices → total per stream.
• Rule-based advisor: Ranked peso-valued actions (8% election, BMBE gating, OSD vs itemized, ₱90k bonus envelope, VAT-threshold timing) with citations (NIRC, TRAIN, CREATE, RA 9178, RRs).

21 Standalone Calculators

Independent state (not reading the profile) for focused what-ifs: freelancer, employee, variable-income, mixed, rental, passive-income; net-pay, 13th-month, overtime, contributions; corporate, VAT/percentage, BMBE, sole-prop-vs-corp, EWT; property transfer (5 modes); penalties, closure-penalty, filing-calendar; form-finder, 1701Q worksheet.

Offline-First + Editable Rates

• Editable rates (/settings): Every figure in the lib/taxConfig.js registry, with per-value revert/reset/JSON import-export. Survives rate changes without redeploy.
• Offline-first + sync: localStorage mirror, window-event pushes, merge policy (unsent local wins on sign-in, history merge-by-id). Guest → Google/email upgrade preserves rows.
• History (/history): Full-figure snapshots, filter chips, expandable rows, JSON export, filing countdown + calendar + form finder.

System Architecture

Main API Endpoints (Next.js Route Handlers)

Impact & Key Takeaways

Moving from Calculator Dump → Ranked Action Plan turns “you owe ₱X” into “do these 3 legal things to owe less, here’s how much each saves.”

• Engineering Growth: Built a pure-function tax library (employeeTax, freelancerTax, mixedIncomeTax, corporateTax, ...) cleanly separated from React, plus offline-first sync with lossless guest upgrades.
• Domain Insight: Tax software is trust software — every figure needs a citation and a walkthrough, or users won’t act on it.

Roadmap

• Short-Term: Align auth error copy, keep bracket-boundary smoke tests green, verify build + lint clean.
• Medium-Term: Expanded filing-calendar coverage and form-finder depth.
• Long-Term: CPA-review pipeline for complex cases beyond simple profiles.

How to Run This Project

git clone https://github.com/jerohalili/moneta.git
cd moneta
npm install
cp .env.example .env.local
# set DATABASE_URL, BETTER_AUTH_SECRET, BETTER_AUTH_URL
# optional: AUTH_GOOGLE_ID + AUTH_GOOGLE_SECRET
npx drizzle-kit push
npm run dev
# open http://localhost:3000 — fastest entry: one-tap guest account