What if I told you tenants in Korea hand their landlord $200,000... with no monthly rent?
That's the Jeonse (전세) system — and it's unlike anything else in the world.
I'm currently dealing with a nightmare tenant situation in Seoul, and it pushed me to start building a tool to help others like me. Here's the story.
🏠 Korea's Rental System, Explained in 60 Seconds
In most countries, you rent an apartment by paying monthly. Korea has that too (called Wolse / 월세), but the dominant system for decades has been Jeonse (전세):
- You give your landlord a massive lump-sum deposit — often 50-80% of the property's value
- We're talking $100K–$300K+ USD for a typical apartment
- You pay zero monthly rent
- The landlord invests your deposit and keeps the returns
- When your lease ends (usually 2 years), you get 100% of your deposit back
Sounds great in theory. In practice? It's a minefield.
💥 The Problems I'm Facing Right Now
I'm a tenant in Seoul, and here's what I'm dealing with right now:
1. 🔇 Landlord Gone Silent
My lease is ending and I need my deposit back. The landlord? Completely unreachable. No calls, no texts, nothing. This is terrifyingly common in Korea.
2. 📜 Automatic Lease Renewal Trap (묵시적 갱신)
In Korea, if neither party gives notice before the lease ends, the lease automatically renews under the same terms. Sounds tenant-friendly, but it creates a grey zone where landlords exploit ambiguity about when they actually have to return your deposit.
3. 📮 Sending Legal Notices (내용증명)
To protect your rights, you need to send a certified legal notice (내용증명) — Korea's version of a formal demand letter. But the process is confusing, the templates are hard to find, and most tenants don't even know they need to do this.
4. 💸 Getting Your Deposit Back
Even after doing everything right, actually recovering your deposit can take months or years. Some tenants end up in court. Some never get it back at all — especially when landlords are overleveraged or the property value has dropped below the deposit amount.
💡 The Idea: DoNotPay, But for Korean Tenants
I'm building a tool that helps Korean tenants navigate and fight back — think of it as DoNotPay but specifically for Korea's rental system.
Here's what I'm starting with:
- 📋 Legal notice generator — Fill in your details, get a proper 내용증명 ready to send
- ⏰ Deadline tracker — Know exactly when to send notices, when your rights kick in, and what happens if you miss a date
- 📚 Step-by-step guides — Plain-language walkthroughs of the deposit recovery process
- 🤖 AI-powered Q&A — Ask questions about your specific situation in natural language
The tech stack so far: Next.js + TypeScript on the frontend, with plans for a Korean legal NLP layer.
🛠 Why I'm Building in Public
Because this problem affects millions of Koreans and the existing resources are:
- Scattered across government websites
- Written in dense legal Korean
- Basically impossible for younger or first-time tenants to navigate
I want to document the journey — the legal research, the technical decisions, and the wins and losses along the way.
🙋 Want to Follow Along?
If this sounds interesting — whether you're curious about Korea's wild rental system, interested in legal-tech, or building something in public yourself — follow me here on Dev.to. I'll be posting updates as I build.
And if you've dealt with similar tenant issues anywhere in the world, I'd love to hear your story in the comments. 👇
Building something that matters, one commit at a time. 🚀
💬 Discussion
Have you ever built something to solve your own legal/bureaucratic problem? I think there's a huge untapped space for "legal tech for normal people" — not lawyers, just regular people stuck in confusing systems. Would love to hear your experiences.
🛠️ More Tools I'm Building
I build free, browser-based tools that solve real problems — no signups, no ads:
👉 DevTools Hub — 18+ Free Tools — JSON formatter, regex tester, hash generator & more. Try any in 5 seconds.
👉 DonFlow — Budget Tracker — Plan vs. reality budgeting. Perfect if you're managing a Jeonse deposit recovery budget.
📦 For Developers Building Legal/Civic Tech
- Developer Cheat Sheet Bundle — Git, terminal, regex essentials. Free to start.
- AI Agent Prompts — Templates for building AI-powered tools like this tenant rights project.
⭐ Follow my GitHub — This tenant tool will be open source when ready.
Drop a ❤️ if you think legal tech needs more indie builders.
📘 Free resource: I documented my entire journey from $0 to building 15 digital products into The $0 Developer Playbook — free strategies for devs building their first product.
Want templates and math? The Extended Edition ($7) includes a 30-day launch calendar, copy templates, and traffic calculators.
Top comments (5)
the jeonse system is wild, honestly never heard of it before this post. building tools for local legal problems is rough - models are trained so heavily on English and US/EU law that they give confidently wrong answers on Korean tenancy stuff. ran into similar walls building tools that touched Eastern European legal contexts, the local legal corpus is just not represented in training data at all. you basically become a domain expert yourself and have to curate from actual legal sources rather than trusting the LLM. good luck with the landlord situation, that sounds genuinely stressful.
You nailed it — the AI/LLM limitation for Korean legal content is real. Most models confidently generate wrong answers about Korean rental law because they're trained on US/EU legal frameworks. That's exactly why I went with a rule-based approach: hardcoded legal references (Housing Lease Protection Act articles), not AI-generated advice. For something as high-stakes as deposit disputes worth tens of thousands of dollars, "confidently wrong" is worse than no answer at all. Great observation!
Great suggestion on react-pdf! I'm currently using html2pdf.js for the 내용증명 generator — works well enough for now but I'll definitely look into react-pdf for the next iteration. And yeah, the 전세 system is wild — basically lending your entire apartment deposit to the landlord as a loan. Glad you found it interesting!
This is such a cool use case for tech. The Jeonse system is wild - I had no idea tenants were putting up that kind of money with basically no safety net.
For the legal notice generator, have you thought about using something like react-pdf or puppeteer to generate properly formatted PDFs? In my experience with document generation tools, having the output look "official" makes a huge difference in how seriously it gets taken. Also if you're doing Korean NLP, you might want to look into KoNLPy for tokenization - legal Korean has a lot of specialized vocab that general-purpose models struggle with.
The deadline tracker is probably the most immediately useful feature imo. Missing a notice window by even a day can change everything in legal situations. Push notifications would be huge there.
Good luck with your situation too - hope you get your deposit back.
Thanks! The Jeonse system really is unique — billions of won at stake with almost no safety net for tenants. That's exactly why I built this: most tenants don't even know their legal options until it's too late. The tool walks them through diagnosis → timeline calculation → automatic legal letter generation. Still early stage but the response from Korean communities has been encouraging!