--- title: "Marketplace Seller Onboarding Software: KYC & KYB | Fynex" description: "Marketplace seller onboarding software with KYC and KYB inside your own signup: individuals and companies, verified under e-money permissions via Fondy, feeding split payouts." url: "/uk/marketplaces/seller-onboarding" --- Fynex is an AI-native finance operations platform — agentic finance — that automates and orchestrates end-to-end financial workflows for businesses. This page covers seller onboarding: verifying sellers at volume and getting them payable, with KYB and risk in one flow. Fynex works alongside Stripe Connect, Adyen for Platforms and Persona rather than replacing them. This page is relevant when a platform is onboarding sellers at volume and wants verification, payout setup and risk handled in a single flow. # Onboard sellers *without dropping them* Run KYC and KYB inside your own signup, so sellers verify without leaving your product. Stay compliant, cut the fraud that lands on your platform, and keep the conversion that bolted-on verification kills. *Marketplace building blocks.* ## KYC that bounces sellers out of your flow costs you sign-ups Every marketplace has to verify its sellers, and every option costs something. Stripe Connect offers Stripe-hosted, embedded or API onboarding, but the verification belongs to Stripe's account model and the payouts stay on Stripe's rails. Standalone KYB vendors verify the business, then leave you to wire the result into payouts yourself. Meanwhile the fraud that slips through lands on your platform as failed cards and chargebacks. ## How seller onboarding runs on Fynex Verify inside your product, approve in the background, keep control. 1. **KYC and KYB inside your own flow** — Sellers verify in your product, not bounced to a third-party page. You collect what you need; approvals happen in the background without breaking the signup. 2. **Cut fraud before it reaches payouts** — Real identity and business checks at onboarding stop the failed-card bombardment and fake sellers that otherwise land on your platform as chargebacks. 3. **Stay compliant as you scale markets** — [KYB and KYC](https://docs.fynex.ai/payments-api/v1/docs/onboarding) are the switch that turns each seller on — handled under our e-money permissions via Fondy Ltd, so compliance keeps pace as you add sellers and countries. ## The same job, with the leaks closed Point tools solve part of it. Fynex runs the whole thing on one platform. | The problem | Other platforms (Stripe Connect onboarding) | Fynex | |---|---|---| | Verify without losing the seller | Hosted form, or an embedded component you integrate and keep current. | Embedded KYC/KYB inside your own signup. | | Onboard individuals, not just companies | Business-detail steps individuals can't complete. | Flows that fit sole traders and companies alike. | | Keep fraud off your books | Weak checks; failed cards and chargebacks land on you. | Real KYC/KYB stops bad actors at the door. | | Scale to new markets | Re-solve compliance per country yourself. | Verification handled under e-money permissions via Fondy Ltd. | ## Questions, answered ### What is the difference between KYC and KYB? [KYC (Know Your Customer)](/glossary/kyc/) verifies an individual's identity; [KYB (Know Your Business)](/glossary/kyb/) confirms a company is legitimate and identifies who controls it. A marketplace onboarding sellers usually needs both — KYC on the person, KYB on the business. Fynex runs both, embedded inside your own signup flow. ### How does Fynex onboard sellers without hurting conversion? KYC and KYB run inside your product, so sellers never leave your signup. You collect what you need in your own flow, checks are staged so a seller can start before every document lands, and approvals happen in the background. A verified seller is immediately set up for split payouts, with no second onboarding for the payout side. ### Which KYB providers are recommended for marketplace seller onboarding? Marketplaces usually choose between four kinds of provider. Platform-payments onboarding such as Stripe Connect (hosted, embedded or API). A payout layer with KYC/KYB built in, such as Fynex, where the verified seller is ready for split payouts. Standalone identity and KYB vendors such as Persona, Onfido, Sumsub or, for US businesses, Middesk. And your own build on a vendor's API. The deciding question is who carries the verification and who then pays the seller. ### How does Stripe Connect onboarding compare? Stripe offers three options: Stripe-hosted onboarding (a Stripe-branded web form), embedded onboarding (a themeable component inside your application) and API onboarding (your own UI, which Stripe says to review at least every 6 months). The first two update automatically for new compliance requirements. The verified account then lives in Stripe's account model, and its payouts go over Stripe's rails. ### Does verifying sellers reduce marketplace fraud? Yes. Real identity and business checks at onboarding are what stop fake sellers and the failed-card bombardment that otherwise reaches your platform as chargebacks and negative balances. Because Fynex is the one holding funds and running KYB, that risk is handled at the door rather than after the money moves. ### Can Fynex onboard both individuals and registered businesses? Yes. The flow fits sole traders and individual sellers as well as registered companies, so you're not forcing business-detail steps on a person who doesn't have them — a common failure point with off-the-shelf Connect onboarding. ### Is seller onboarding available through an API? Yes. Verification runs inside your own sign-up flow, and the [onboarding section of the API reference](https://docs.fynex.ai/payments-api/v1/docs/onboarding) documents the states a seller moves through, with [verification patterns](https://docs.fynex.ai/payments-api/v1/docs/verification-patterns) covering how to stage checks so a seller can start before every document lands. ## The rest of the marketplace money layer Every building block below runs on the same platform. Start with one, or run the whole stack. - **Split payments** — Divide one payment across sellers, your fee and partners — by rule, in real time. - **Escrow & held funds** — Hold a buyer's payment until the work is delivered, then release it to the seller. - **Delayed capture** — Authorize a card at checkout and capture the payment later, when you're ready. - **Platform commission** — Take your cut automatically at settlement — set your take rate once and keep it. - **Payout scheduling** — Pay sellers on schedule or by rule — mass, same-day or timed, by ACH or Faster Payments. - **Marketplace wallets** — Give each seller a stored balance to hold, top up and withdraw — per currency, one ledger. - **Balance management** — One ledger for every balance, split, hold and payout — reconciled to the transaction. ## Find what you're leaking, for free Send us your setup. We run a free diagnostic and show you what your payment stack costs you today. > One recent diagnostic found £2M in hidden fees across 10 processors for a proptech client. ## Your money, held under a licence, not a promise We can be your Merchant of Record, with your funds held by a licensed e-money institution. Most tools can't. - **Your funds, safeguarded** — Customer funds are held by Fondy Ltd, an FCA-authorised e-money institution (FRN 900705). - **PCI DSS Level 1** — The highest card-data security standard, on by default. - **Audit logs** — Every movement traceable and ready for review. - **Built-in KYC / KYB** — The switch that turns the business on. ## Verify every seller. *Without losing a single one* --- The AI finance layer for platforms and operators. It runs the money chain and keeps more of it in your business. One platform instead of a dozen. 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