What is Toss? How a Simple App Built Korea’s 30 Million-User Fintech Platform

Toss, operated by Viva Republica, isn’t just South Korea’s most popular fintech app — it’s the clearest proof that the Asian super app model can work outside China and Southeast Asia. Founded in 2013 by former dentist Lee Seung-gun after eight failed startups, Toss launched in 2015 as a peer-to-peer money transfer tool and has since grown into a full financial super app spanning banking, securities, insurance, and biometric payments. As of mid-2025, six in ten South Koreans — over 30 million registered users — have the app on their phone, and 25 million of them open it at least once a month (Korea Herald, July 2025). Consolidated revenue hit KRW 1.96 trillion (approximately US$1.3 billion) in 2024, up 43% year-on-year, and Viva Republica posted its first-ever annual net profit of KRW 21.3 billion (PR Newswire, March 2025). With a US IPO planned for Q2 2026 at a valuation north of US$10 billion, Toss is about to become the most high-profile Korean fintech listing since Coupang‘s US$4.6 billion debut in 2021. Here’s how it got there — and what could trip it up.

How did Toss go from a payment app to a financial super app?

The short version: one service at a time, always starting from what users were already doing inside the app.

When Toss launched in 2015, its sole trick was letting Koreans send money to each other without the grotesque authentication rituals that Korean banking apps demanded — certificates, security cards, and enough passwords to fill a small notebook. That single UX improvement attracted millions of users fast. But Lee Seung-gun’s founding thesis, shaped by those eight earlier failures, was that Korean financial services had a structural gap. Legacy banks were slow, fragmented across dozens of apps, and built for desktop. A mobile-first platform that aggregated everything into one clean interface could own the relationship.

So Toss stacked services. Credit scores came first — giving users a free look at their rating, which at the time was something Korean banks charged for. Then came loan comparison, insurance comparison, and eventually stock trading through Toss Securities (launched 2021) and full banking through Toss Bank (launched 2021). Each vertical fed the next: users who checked their credit score were nudged toward loans; users who received payments opened savings accounts; users who saved started investing. By 2024, the Toss app housed more than 40 distinct financial services under a single login (Fortune, April 2025).

That flywheel is the growth story. It isn’t a payments company that bolted on extras — it’s a distribution engine that happens to have started with payments.

How does Toss make money?

Toss’s consolidated revenue for 2024 came in at KRW 1.96 trillion (US$1.3 billion), a 43% jump from the prior year. In H1 2025, the pace accelerated: consolidated revenue topped KRW 1.2 trillion, up 35% year-on-year, and Q2 2025 alone delivered KRW 668 billion, a 41% increase (PR Newswire, August 2025). Revenue breaks down across three main subsidiaries and the parent platform.

Toss Securities was the standout performer in 2024. Revenue more than doubled to KRW 426.6 billion, and the unit posted its first-ever operating profit of KRW 149.2 billion (Korea Herald, February 2025). The surge came from Korean retail investors piling into US equities — overseas stock trading volume on Toss Securities rose 211% — alongside growing foreign exchange fee income. The brokerage has made fractional US stock investing so frictionless that it’s become an acquisition channel for the broader app.

Toss Bank contributed steadily growing interest income as its loan book expanded (more on that below). Toss (standalone) — the parent app covering payments, advertising, and platform fees — recorded KRW 587 billion in revenue for 2024, a 75% year-on-year leap, driven by transaction fees and a growing advertising business that monetises the app’s enormous daily traffic.

Toss Insurance operates primarily as a comparison and distribution platform, routing users to underwriters rather than carrying risk on its own balance sheet. While specific standalone figures aren’t broken out, the division contributes margin through commissions and fits the broader pattern: Toss monetises attention and trust, not just transactions.

How big is Toss Bank?

Big enough to worry incumbents. Toss Bank launched in October 2021, making it the third internet-only bank in South Korea after KakaoBank and K Bank. It reached profitability in its second full year of operation — no small feat for a neobank — and in 2025, net profit nearly doubled to KRW 96.8 billion (Digital Today, February 2026).

Deposits crossed KRW 30 trillion for the first time in 2025, up KRW 2.5 trillion year-on-year, with the share of savings deposits rising to 45% of the total — a meaningful shift that makes the funding base cheaper and more stable. Customer numbers hit 14.23 million, narrowing the gap with second-placed K Bank (15.53 million) to roughly one million accounts. KakaoBank still leads with over 24 million customers, but Toss Bank is closing ground faster than anyone expected.

The bank’s strategy mirrors the broader Toss playbook: acquire users cheaply through the super app, then cross-sell lending and savings products. Because Toss Bank sits inside an app that 25 million people already use monthly, its customer acquisition cost is a fraction of what standalone neobanks spend. That embedded distribution advantage is difficult to replicate.

What makes Toss different from Kakao Pay and Naver Pay?

The three get lumped together, but their models are different.

Kakao Pay (over 40 million registered users) is a payments and financial services layer built on top of KakaoTalk, South Korea’s dominant messaging app. Its advantage is distribution through a chat platform that virtually every Korean already uses. But Kakao Pay doesn’t operate its own bank, and its financial product range is narrower than Toss’s.

Naver Pay is an e-commerce payments rail, tightly integrated with Naver Shopping and Naver Smart Store. It dominates online checkout flows but doesn’t aspire to be a full financial super app. Its strength is merchant coverage and transaction volume within the Naver ecosystem.

Toss is the only one of the three that owns the full stack: payments, banking, securities, and insurance under one roof with no parent platform dependency. Kakao Pay needs KakaoTalk for distribution. Naver Pay needs Naver Shopping for volume. Toss is the destination itself. That independence is a double-edged sword — it means Toss has to earn every user on its own — but it also means the company captures more of the value chain and isn’t beholden to another platform’s strategic priorities.

In January 2025, South Korea’s Financial Services Commission finalised a unified national QR-code standard mandating compatibility across Kakao Pay, Naver Pay, Toss, and card-issuer wallets. That levels the playing field on offline merchant acceptance and arguably benefits Toss most, since it had the smallest offline payment footprint of the three.

What are the risks?

Three stand out.

Regulatory tightening. Korean financial regulators have grown more assertive about internet-only banks’ internal controls. Toss Bank’s rapid lending growth has drawn scrutiny, and any macro-driven spike in delinquencies could force the bank to slow down precisely when it needs to scale. Korea’s data privacy framework is also evolving — Toss’s FacePay biometric payments product (over 2 million registered users and 240,000 merchant locations as of early 2026) is the only face-payment system to have undergone a preliminary review by the Personal Information Protection Commission, but regulatory mood can shift quickly.

Concentration risk. Toss Securities’ 2024 breakout was driven overwhelmingly by Korean retail investors trading US stocks. If cross-border equity enthusiasm cools — or if regulators impose tighter foreign exchange controls — the brokerage’s revenue could snap back hard. The unit went from years of losses to KRW 149 billion in operating profit in a single year, which suggests high operational leverage in both directions.

Competitive pressure. KakaoBank is profitable, entrenched, and backed by Korea’s most powerful consumer tech ecosystem. Naver continues to expand its financial services ambitions. And traditional Korean banks, after years of complacency, are finally investing seriously in mobile experiences. Toss’s UX edge is real but not permanent.

What’s the outlook?

The headline event is the planned US IPO in Q2 2026, which Reuters reported in July 2025. Viva Republica is targeting a valuation above US$10 billion — potentially stretching to US$15 billion in favourable conditions — with the offering expected to raise between US$2 billion and US$3 billion. If it goes ahead, it would be the largest US IPO by a Korean company since Coupang.

The timing makes sense. Toss has the growth rate (revenue up 35-43% year-on-year), the profitability inflection (first annual net profit in 2024, with Q1 2025 alone delivering KRW 48.9 billion in net profit), and a product roadmap that gives public-market investors something to model forward. FacePay, currently in 240,000 stores, is targeting one million merchant locations by end of 2026 — if that lands, it transforms Toss from an app into physical-world payments infrastructure.

Beyond the IPO, the bigger question is whether Toss can expand beyond Korea. Lee Seung-gun has spoken publicly about Southeast Asia and Japan as target markets, though concrete international moves have been limited so far. The super app model is proven domestically, but replicating it in markets where Grab, GCash, or PayPay already dominate will require a different kind of execution.

For now, Toss’s trajectory is hard to argue with: a decade-old company that went from a simple money transfer tool to a KRW 2 trillion revenue platform used by the majority of South Korea’s adult population. The growth isn’t accidental — it’s the compound effect of solving one problem well, earning trust, and then systematically expanding into every adjacent financial need. Whether the public markets will reward that story at a US$10 billion-plus valuation is the next chapter.