Below is a practical, decision-focused guide to marketplace payment solutions (what to offer buyers, what to pay vendors, and how to architect those flows). It covers common payment flows, required features, compliance/tax considerations, and realistic provider options so you can pick or evaluate platforms quickly.

1. Core payment flows for marketplaces

• Buyer pays seller directly (Direct charge): buyer is charged and funds go straight to the vendor’s account. Platform has lower liability but less control.
• Platform charges and pays sellers (Platform/On-behalf-of): platform captures buyer payment, remits commission and vendor payout. Gives platform control for refunds, fees, escrow.
• Split payments (instant split): single buyer charge is split at transaction time between platform fee and vendor share (reduces reconciliation work).
• Escrow / delayed release: hold funds until conditions are met (goods delivered, milestone completed) — useful for high-value or dispute-prone transactions.
• Payouts-only (vendor payout rails): platform collects by other means (e.g., invoices) and only needs to disburse funds to sellers.

2. Must-have features for a marketplace

• Multi-party payments / split payments support.
• Vendor onboarding and identity verification (KYC) integrated.
• Flexible payout scheduling (instant, same-day, weekly).
• Refunds & dispute/chargeback handling that preserve correct accounting.
• Escrow / conditional release capability (if needed).
• Robust APIs, SDKs, and good documentation.
• Multi-currency support and currency conversion (if international).
• Fee & commission routing (platform fee, service fees, tax collection).
• Reporting, reconciliation tools, and webhooks for events.
• PCI-compliance scope minimization (tokenization, hosted fields).
• Fraud detection & risk management (device fingerprinting, velocity checks).
• Tax reporting support (e.g., 1099-K data in US) and VAT collection for EU.

3. Regulatory & compliance points to plan for

• KYC/AML: collecting vendor identity, SSN/EIN in US, and verification workflows.
• Money transmitter/licensing: depending on your model and jurisdictions, you may need licenses or to use a payments provider with licensing.
• Tax reporting: platforms often must provide information to vendors (1099) and collect VAT/GST in some regions.
• Data privacy: comply with applicable privacy laws (CCPA, GDPR).
• PCI scope: reduce scope by using hosted components or tokenization.

4. User experience considerations

• Fast, transparent vendor onboarding (minimize fields; do KYC asynchronously).
• Clear fee breakdowns shown to buyers and vendors.
• Predictable payout timing; offer faster payouts as premium.
• Automated reconciliation and downloadable statements for vendors.
• Clear dispute resolution and refund policies.

5. Typical fee structure elements (what to budget for)

• Buyer card processing fee (percentage + fixed).
• Marketplace/platform cut (flat or percentage).
• Payout fees (per-route, instant payout fees).
• Currency conversion or cross-border fees.
• KYC/verification fees (sometimes included).
• Monthly platform/provider fees and chargeback fees.

6. Common marketplace architectures (technical)

• Fully-hosted payments (provider handles checkout, onboarding widgets).
• API-based (you host checkout but use tokenization; more control).
• Hybrid (hosted checkout + API vendor management).
• Webhook-driven backend to record payment events and trigger payouts.

7. Providers to evaluate (well-known options and use-cases)

• Stripe Connect — strong developer APIs, split payments, Connect On Behalf Of, instant payouts; very popular for SaaS & large marketplaces.
• PayPal Commerce Platform / Braintree — buyer familiarity, global reach, supports marketplace flows and payouts.
• Adyen MarketPay — enterprise-focused, robust global rails and risk tools.
• MANGOPAY — European marketplaces; supports escrow and splitting.
• Mollie / Checkout.com — regional/global options with marketplace features.
• Payoneer / Hyperwallet (PayPal) — payouts-focused (mass payouts, cross-border).
• Tipalti — accounts-payable + mass payouts, good for high-volume vendor payouts and tax compliance.
• MANGOPAY, Tink, Rapyd, Flutterwave — regional/global alternatives with local rails (APAC, Africa, LATAM).
• Traditional PSPs / banks with marketplace modules — for heavily regulated industries or where custom banking relationships needed.

(Provider choice depends on geography, volume, desired control, and regulatory needs.)

8. Which provider/model to pick (quick decision rules)

• If you want fastest time-to-market and developer-friendly APIs: Stripe Connect or PayPal Commerce Platform.
• If you need enterprise/global scale with advanced risk/fraud controls: Adyen MarketPay or Checkout.com.
• If you need localized payment methods in many emerging markets: Rapyd, Flutterwave, or local specialists.
• If your primary requirement is mass cross-border payouts and tax compliance: Tipalti, Payoneer, or Hyperwallet.
• If your marketplace needs escrow/conditional release as a core feature: choose providers that offer escrow natively (MANGOPAY, some Connect setups with hold-until-capture workflows, or custom escrow via platform-controlled accounts).

9. Implementation & operational checklist (practical next steps)

• Map transaction lifecycle: buyer checkout → potential refunds → dispute scenarios → payout schedule.
• Decide who is merchant of record (MoR) — platform or seller — and legal/tax implications.
• Design vendor onboarding form and KYC flow; integrate verification API.
• Implement webhooks / event-handling for payment, dispute, payout events.
• Build reconciliation reports and accounting mappings (fees, reserves, refunds).
• Plan for fraud prevention (3DS, velocity throttles), and set thresholds.
• Run compliance review (legal + tax) for all jurisdictions where you operate.

10. Risks & mitigation

• Chargebacks and fraud: use fraud tools, hold reserves, require KYC.
• Regulatory risk: partner with providers that hold required licenses or consult counsel.
• Liquidity / float risk: avoid models that make you a money transmitter unless you plan for licensing.

11. Typical integrations & add-ons

• Accounting software connectors (QuickBooks, Xero).
• KYC/ID providers (Jumio, Onfido) if provider doesn’t include verification.
• Fraud platforms (Sift, Riskified) for high-risk verticals.
• Tax engines (Avalara, TaxJar) for VAT/sales tax automation.

Summary / recommendation

• For most new US-based marketplaces that need developer-friendly, flexible split payments and fast rollout: start with Stripe Connect or PayPal Commerce Platform and use their built-in KYC and split-payment features. Add a mass-payout partner (Tipalti/Hyperwallet/Payoneer) only if you require advanced global payout features or specific local rails.
• For enterprise/global or regulated verticals, evaluate Adyen MarketPay or Checkout.com and consult legal on money-transmitter risk and tax obligations.

If you’d like, I can:

• recommend 2–3 specific providers tailored to your country mix, transaction size, and volume, or
• sketch the exact data model/webhook flows for a chosen provider (e.g., Stripe Connect split payments + escrow).