Building a Tax Accounting PWA for Vietnamese Small Businesses ☕

Apr 12, 2026 · the story of how i mass-produced an entire app

The Problem 🤔

In Vietnam, millions of household businesses must keep accounting records under Circular 152/2025. Most owners are not tech-savvy. We are talking about sugarcane sellers, grocery stores, and your neighbor who sells banh mi from a cart.

The Solution 💡

I built HKD Accounting — a free, offline-first PWA. No login, no cloud, no subscription. Open it, tap some buttons, get your tax form.

The Stack 🛠

• sql.js — A whole SQLite database. In your browser. In WASM. Living its best life.
• Next.js 14 — Because every project needs a framework with a cool name
• html2canvas + jsPDF — Renders HTML → screenshot → PDF. Hacky? Yes. Works? Also yes.
• ExcelJS — Generates .xlsx that match government templates. The tax office cannot tell.

UX: Designing for Aunties 👵

The hardest part was not the code — it was making it usable for someone who might struggle with a smartphone.

• Two modes — "Simple" for tax-only, "Full" for POS nerds like me
• Smart amount input — Type "200", get 200k/2M/20M suggestions. No zero-counting.
• Guided tour — First-time spotlight overlay. Like a video game tutorial but for taxes.

Tax Compliance 📋

The Debt System 💸

Vietnamese small businesses run on trust. "Ghi nợ" (write down the debt) happens 10 times a day. So I built a full contact + debt tracking system.

What I Learned 🧠

• SQLite in WASM is legit — Full SQL, indexes, transactions. All in the browser.
• PWAs on iOS still kinda suck — Service worker lifecycle quirks. Apple why.
• 10x more UX iteration for non-tech users — What is obvious to you is cryptic to your auntie.
• Vietnamese diacritics in PDFs — html2canvas is the only way. I tried everything else.

Try It 🚀

The app is live at hkd.tamduongs.com. Free forever. Works offline. Auntie-approved. 😎

Source code? nah, private for now. Stay chill. ✌️