What is Payment Service Provider?
Also: PSP
A vendor that provides payment-acceptance technology, gateway, vaulting, reporting, and sometimes acquiring, bundled as a single commercial relationship.
A Payment Service Provider (PSP) is a financial services company that provides merchants with a comprehensive solution for accepting electronic payments.
PSPs act as a crucial intermediary, connecting merchants to the wider payments ecosystem, including acquiring banks, card schemes like Visa and Mastercard, and various alternative payment methods (APMs).
Their service typically bundles a payment gateway for secure data transmission, merchant account provisioning, fraud screening tools, and consolidated transaction reporting into a single platform and contract.
This greatly simplifies the process for a merchant, who would otherwise need to establish separate technical and commercial relationships with multiple financial entities.
The mechanical flow involves the PSP receiving transaction details from the merchant's Checkout, securely forwarding them to the relevant acquirer or payment network, and returning the authorisation response.
Many PSPs operate as 'aggregators', processing transactions for numerous smaller merchants under a single, master Merchant Identification Number (MID). This speeds up onboarding but gives the merchant less direct control.
Other PSPs act as Independent Sales Organisations (ISOs) or technology providers, facilitating a direct MID for the merchant with an acquirer.
A common nuance is the distinction between a PSP and an acquirer; while many modern PSPs are also licensed acquirers, some are purely technology resellers, which can affect support quality and pricing transparency.
Worked example
Consider a UK merchant selling a subscription box for £40. They use a popular PSP that offers a Blended pricing model of 2.5% + 20p for European cards.
When a customer subscribes, the PSP's gateway captures the card details.
- The PSP processes the £40 payment.
- The fee is calculated: (£40 * 0.025) + £0.20 = £1.00 + £0.20 = £1.20.
- The PSP collects £40 from the customer's bank via the card schemes and acquirer.
- After a settlement period, typically 2-3 business days, the PSP deposits £38.80 (£40 - £1.20) into the merchant's bank account.
While simple, this blended fee obscures the true underlying costs. The actual interchange for this 'card-on-file' transaction might have been only 0.30% (£0.12), with scheme and acquirer fees adding another 0.25% (£0.10).
The PSP's margin in this case is £0.98, significantly higher than the base processing cost.
Scheme notes
PSPs, particularly those acting as aggregators, are responsible for ensuring all their sub-merchants comply with card scheme rules. Schemes like Visa and Mastercard hold the PSP accountable for the collective activity under its master MID.
If a subset of merchants generates excessive chargebacks, the entire PSP portfolio could be placed into a monitoring programme, such as the Visa Fraud Monitoring Program (VFMP) or Mastercard's Excessive Chargeback Program (ECP).
Furthermore, if a sub-merchant engages in illicit activity, they can be placed on the MATCH (Member Alert to Control High-Risk Merchants) list by Mastercard, making it difficult for them to get an account elsewhere.
Schemes ultimately view the aggregator PSP as the 'merchant of record' from a risk perspective.
Why it matters for merchants
Using a PSP offers convenience and rapid onboarding, which is iDEAL for new or smaller businesses. However, reliance on a single PSP's master MID creates a single point of failure; if their account is suspended, the merchant cannot process payments.
Blended pricing models are simple to understand but are often more expensive for merchants as they scale, hiding the true cost of interchange. Cardflo's payment orchestration platform allows merchants to connect to multiple PSPs and acquirers.
This avoids vendor lock-in, enables smart routing to lower costs and increase approval rates, and provides a consolidated view of payments without forcing the merchant to rely on a single provider's infrastructure.
Frequently asked
How does a PSP differ from a traditional merchant acquirer?
A traditional acquirer focuses primarily on the settlement of funds and providing a merchant account, whereas a PSP typically offers a broader technology stack including the gateway and risk management tools.
Some PSPs provide their own acquiring services, while others operate as gateways that must be linked to a separate third-party acquiring bank.
Does using a PSP remove the requirement for PCI DSS compliance?
Using a PSP reduces the compliance burden by handling sensitive card data through hosted fields or tokenisation, but it does not eliminate it entirely.
Merchants generally still need to complete a simplified Self-Assessment Questionnaire (SAQ) to prove that they do not store or transmit cardiovascular data on their own local servers.
What is the difference between a PSP and a payment gateway?
A payment gateway is a technology that securely transmits payment data from the merchant to the acquirer. A PSP is a broader service company that almost always includes a gateway, but also typically provides merchant accounts, reporting, and settlement of funds.
Think of the gateway as a component, while the PSP is the comprehensive service provider that uses that component to deliver a full payment solution.
Why would Stripe or PayPal reject a business that another PSP would accept?
Large PSPs like Stripe and PayPal have a relatively conservative risk appetite because they operate at a massive scale using an aggregator model.
Their automated onboarding and risk systems are designed to filter out entire categories of businesses deemed high-risk, such as those in travel, nutra, or digital services.
Other, more specialised PSPs are willing to underwrite these businesses, often with more detailed KYB checks and tailored risk settings like a rolling reserve.
Am I better off with a PSP's Blended pricing or an interchange-plus model?
For businesses with low transaction volumes or small ticket sizes, Blended pricing can be simpler. However, as your volume grows or average ticket size increases, an interchange-plus (IC+) model is almost always more cost-effective.
IC+ pricing is transparent, showing the non-negotiable interchange and scheme fees separately from the acquirer's margin. This allows you to see exactly what you are paying for and generally results in lower overall costs.
If I use a PSP, do I still need to be PCI DSS compliant?
Yes, but the scope of your compliance is significantly reduced. By using a PSP's hosted Checkout page or client-side encryption libraries, you ensure that sensitive cardholder data never touches your servers.
This means you can typically validate your compliance using the simplest Self-Assessment Questionnaire (SAQ), usually SAQ A, which is far less burdensome than the requirements for storing or handling raw card data yourself.
How quickly can I get set up with a PSP?
Onboarding speed varies. Aggregator PSPs like Stripe can often approve low-risk businesses in a matter of minutes or hours through an automated process.
For more specialised PSPs or those providing a direct MID, the process involves more thorough Know Your Business (KYB) checks and can take several days to a few weeks.
The complexity of your business model, your industry's risk profile, and the quality of your documentation will all influence the timeline.
See how Payment Service Provider plays out in practice
Industries and regions where this term drives real acquiring, routing, or dispute decisions.
Related terms
The licensed bank or financial institution that holds the merchant's MID and settles card transactions on the merchant's behalf.
A technical layer that encrypts card data, forwards authorisation requests to an acquirer, and returns the result to the merchant.
A platform layer that lets a merchant connect to multiple acquirers, APMs, and risk tools through one integration and route transactions intelligently.
A unique identifier issued by an acquirer that ties transactions to a specific merchant account.
Related guides.
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