01

secondhand.fi

The marketplace where Gen Z in Finland buys and sells pre-loved fashion — with AI pricing, virtual try-on, and buyer protection.

Y Combinator S26 Application | secondhand.fi
02 Problem

Selling clothes in Finland is broken

Sources: Tori.fi user research (2025), Vinted market coverage map, internal seller surveys
03 Solution

Full-stack resale marketplace
built for Nordic trust culture

For Sellers

  • AI
    AI auto-fill — snap a photo, get title + description + price suggestion in 3 seconds (Qwen-VL)
  • $
    Dutch auctions — price drops automatically until someone bites. Zero negotiation friction.
  • B
    Business batch upload — outlets, second-hand stores, returns. Upload 100 items at once with size variants.
  • 💰
    Instant payouts — Stripe Connect. Money in your bank next day.

For Buyers

  • 🛡
    Buyer protection — payment held in escrow until buyer confirms receipt. Disputes with evidence.
  • 👗
    Virtual try-on — see how clothes look on you before buying (ComfyUI + SAM3)
  • 📦
    Integrated shipping — Posti SmartPost labels generated automatically. Or meetup zones.
  • 💬
    Real-time chat — negotiate, send offers, counter-offer — all in-app with WebSocket.
04 Market

Secondhand fashion is the fastest-growing segment in retail

$367B
Global secondhand apparel market by 2029
ThredUp 2025 Resale Report / GlobalData
5x
Faster growth than retail clothing
Online resale +23% YoY in 2024 (ThredUp)
€26B
European secondhand market by 2030
€15.9B in 2024 → €26B by 2030 (Cross-Border Commerce EU)

TAM → SAM → SOM

€2.5B
TAM — Nordic secondhand fashion (FI+SE+NO+DK). 27.5M people, €27.3B total fashion market. Secondhand ~10%.
€400M
SAM — Finland online secondhand fashion. 1.4M Finns 18-35, 89% have bought used. €802/yr apparel spend.
€12M
SOM — Year 3: 3% of Finnish online resale. 50% shop C2C online but only 23% use apps — conversion gap.
Sources: ThredUp 2025 Resale Report, Cross-Border Commerce Europe 2024, Globe Monitor Nordic Fashion 2024, Statista Finland population
05

Why Finland? Why now?

  • 🇫🇮
    5.6M people, 95% internet penetration
    Highest digital adoption in EU. Mobile-first culture.
  • ♻️
    89% of under-24s have bought secondhand
    Only 11% never tried it (Posti 2025). 62% have also sold used items. It's cultural, not a trend.
  • 🏪
    No dominant fashion resale player
    Tori.fi = generalist classifieds (€36M rev). Vinted just entered. Bought raised $1.5M pre-seed — market is validated but unowned.
  • 📐
    Small enough to win, big enough to matter
    Win Finland → expand to Nordics (26M people, same culture, same logistics).

Finland → Nordics playbook

Finland 5.6M
+ Sweden 10.5M
+ Norway 5.5M
+ Denmark 5.9M
Total Nordics 27.5M

Same Posti/PostNord logistics, same trust culture, same payment infra (Stripe EU). One codebase, four markets.

06 Traction

Built in 3 months. Solo founder.

18
Backend modules shipped
Auth, AI, payments, chat, shipping, disputes, admin...
148
TypeScript source files
Production-grade NestJS + Next.js 14
9
Item source types supported
Personal, returns, open-box, outlet, deadstock, trade-in...

What's live and working

🤖
AI Analysis
Qwen-VL + GPT-4o-mini
auto-fill listings in 3s
💳
Stripe Payments
Checkout + Connect
auto-payouts every 10 min
📦
Posti Shipping
SmartPost integration
auto-generated labels
🏪
Business Accounts
Batch upload, Y-tunnus
outlet/returns/open-box
07 Business Model

Three revenue streams from day one

5% + €0.70

Buyer Protection Fee

Charged to buyer on every transaction. Min €1.00. Covers escrow, dispute resolution, fraud prevention.

On €25 avg item: €1.95 fee (7.8% effective take rate)

€0.40

Shipping Margin

Fixed margin on every shipped order. Posti base €3.90 → buyer pays €4.30. We keep €0.40.

~70% of orders are shipped = €0.28 blended per txn

€0.99

Listing Bumps

Push listing to top of feed for 24h. Optional, seller-paid. ~5% attach rate expected.

Future: business subscriptions, promoted listings, featured brands.

Blended take rate at scale
~10%
Comparable to Vinted (10.5%), Depop (10%), Poshmark (20%). Conservative — room to add business subscriptions and ads.
08

Competitive landscape

Feature Tori.fi
€36M rev, 3.5M MAU		 Vinted
€813M rev, €5B val		 Bought (ex-Zadaa)
$1.5M pre-seed		 secondhand.fi
In Finland Yes (generalist) Since Nov 2023 Yes Yes
Built-in payments No Yes Yes Yes (Stripe)
Buyer protection No Yes No Yes (escrow)
Integrated shipping No Yes Yes (Wolt) Yes (Posti)
AI auto-fill listings No No Email history AI Yes (Qwen-VL photo)
Virtual try-on No No No Yes (ComfyUI)
Business sellers (B2C) No No No Yes (9 source types)
Dutch auctions No No No Yes
Fashion-focused Everything Yes Yes Yes

Why we win: Bought does AI from email receipts — we do AI from photos (no email access needed). Vinted is generic pan-EU — we're local-first with Posti, Y-tunnus business verification, meetup zones. Self-hosted AI models (Qwen-VL, SAM3) = no API dependency. Virtual try-on = technical moat competitors can't copy in a sprint.

09 Impact

Every item resold = one fewer manufactured

3 kg
CO2 saved per garment resold
Reuse has 70x lower environmental impact (EuRIC 2024)
2,700L
Water saved per garment
One cotton t-shirt requires 2,700L to produce
92M
Tons of textile waste annually
Only 12% of clothing is recycled globally

At 100K transactions/year, secondhand.fi would prevent 360 tons of CO2 and save 270 million liters of water. Sustainability is not our marketing — it's our unit economics. Resale has zero COGS.

Sources: EuRIC / Journal of Circular Economy 2024, ThredUp 2025 Resale Report, Planet Aid
10

Roadmap

Q2 2026 (Now)
  • ✅ MVP complete (148 files)
  • ✅ AI pricing (Qwen-VL)
  • ✅ Stripe payments + payouts
  • ✅ Posti shipping
  • ✅ Business accounts + batch
  • ✅ Virtual try-on
Q3 2026
  • Beta launch in Helsinki
  • First 100 sellers onboarded
  • Partner with 5 outlet stores
  • Aalto University campus launch
  • CSV bulk import for business
Q4 2026
  • 1,000 active sellers
  • Expand to Tampere + Turku
  • Business subscription tiers
  • Promoted listings (ads)
  • Social features (follows, shares)
2027
  • 10,000 active sellers
  • Sweden launch (PostNord)
  • €500K+ monthly GMV
  • Series A readiness
  • Brand partnerships
11

Team

👨‍💻

Solo Founder

Full-stack engineer. Built the entire platform in 3 months.

NestJS Next.js PostgreSQL Stripe ComfyUI PyTorch Docker

Hiring plan (post-funding)

Growth / Community

Helsinki campus ambassadors, seller onboarding, social media.

Frontend Engineer

React Native mobile app. PWA → native conversion.

ML / AI

Pricing models, recommendation engine, image search.

12

The Ask

€500K

Pre-seed round to reach 1,000 active sellers in Finland

40%
Engineering
(hire 2, infra, models)
30%
Growth
(campus launch, seller acquisition)
20%
Operations
(shipping deals, support, legal)
10%
Runway buffer
(18 months runway)

secondhand.fi

The Vinted for the Nordics — with AI, business sellers, and Finnish trust.