PSP

A Payment Service Provider (PSP) sits at the core of how most merchants accept card and digital payments. Understanding what a PSP does — and what it doesn't — is essential for anyone evaluating payment infrastructure or negotiating processing agreements.

What a PSP Does

A PSP provides the full stack required to process a payment:

1. Payment gateway: The technical interface that encrypts and transmits card data from the checkout to the processing network.
2. Processing: Routing the transaction authorization request to the appropriate card network (Visa, Mastercard) and issuing bank.
3. Acquiring: Maintaining the banking relationships required to settle funds into the merchant's bank account.
4. Settlement: Disbursing transaction proceeds to the merchant, typically on T+1 or T+2 basis after netting out fees.
5. Fraud and risk management: Screening transactions for fraud signals and managing chargeback exposure.

PSP vs. Acquirer vs. Gateway

These terms are often used interchangeably but refer to distinct functions:

• A payment gateway is purely a technical layer — it routes data but holds no banking relationship.
• An acquirer is a licensed bank or institution that maintains the merchant account and settles funds.
• A PSP typically bundles gateway and acquiring functions (sometimes through bank partnerships), offering merchants a single point of contact.

Full-stack PSPs like Stripe and Adyen handle all three functions. Specialty gateways like Spreedly or Primer connect to multiple PSPs and acquirers without holding funds themselves.

How to Evaluate a PSP

Selecting a PSP involves more than comparing headline rates. Operators typically assess five dimensions:

1. Market and payment method coverage: A PSP's card acceptance may be global, but support for local payment methods — real-time rails (UPI, PIX, PayNow), wallets (GrabPay, Alipay, M-Pesa), and A2A schemes — varies significantly by region. Confirm native support versus pass-through integrations, which add latency and cost.

2. Pricing model: PSPs offer interchange-plus (cost + fixed margin, transparent), blended (flat rate regardless of card type, simple but opaque), or flat-fee models. IC+ pricing is preferable for merchants with high volume or a card mix skewed toward debit or basic consumer cards.

3. Settlement currency and speed: Most global PSPs settle in USD or EUR on T+1 or T+2. Local currency settlement requires additional banking arrangements and is not universally available. For cross-border merchants, FX markup on settlement is a material cost often buried in the contract.

4. Acquirer redundancy: Relying on a single PSP means a single point of failure. Merchants processing above ~$5M annually typically benefit from a second acquirer relationship for resilience and authorisation rate optimisation through intelligent routing.

5. Compliance and licensing fit: PSPs operating in regulated markets (EU PSD2/SCA, India RBI tokenisation, Brazil BCB) must hold local licences or partner with locally licensed entities. Verify the PSP's regulatory standing in each market before go-live, not after.