What is a PSP and how does it work?

Payment transactions are much more complex than one would think. Customers aren’t particularly interested in knowing how their money reaches the receiver’s account, however, for businesses that deal with payments on a daily basis, it can be useful to know the key factors of payment processing.

What is a PSP?

A PSP is a Payment Service Provider, also called Merchant Service Provider (MSP) or Payment Processor, and it is one of the key players in a payment transaction. PSPs process and manage the entire transaction, actually moving the funds from one account to the other, and serve as a mediator between the Issuing bank, card/payment network and Acquiring bank.

PSPs are responsible for authorising a payment and ensuring that funds are transmitted to the merchant’s account. Every business that takes debit or credit card payments needs to partner with a Payment Service Provider and pay them directly for their services. Some of the most well-known PSPs are PayPal, Square, Stripe, Adyen and GoCardless.

Payment Service Providers help merchants to accept payments and manage their transactionss

How does a payment transaction work?

Though it can seem confusing at first, the basis of payment processing is quite simple. When a customer purchases something online, scans a device or enters their bank information manually, the payment gateway collects the payment information from the Issuing bank and transmits it to the PSP. It is now common to see payment gateways and PSPs merged into the same company, such as Stripe or Braintree.


The Issuing Bank then needs to verify the information through the payment processor, making sure that the payment details are valid and that there are enough funds in the bank account to process the payment. The transaction also has to pass verification checks based on the card’s CVV number or AVS.

CVV means Card Verification Value, and is composed by 3 digits on the back of the card for Visa and MasterCard, or 4 digits in front of the card for American Express. AVS means Address Verification Service, and it is a system used to verify the address and zip code of the cardholder. Both of these are used to ensure the legitimacy of all the data and prevent fraud or identity theft. If all details are correct, the PSP authorises the payment.


Authorisation is one of the main steps of a payment transaction. Merchants can choose between an authorisation hold or capture. Essentially, an authorisation hold means that the payment is authorised by the PSP and ready to be transferred, but it is on hold for the merchant to review the details of the payment before accepting it.

Merchants might choose to put the payment on hold to double check that the payment is legitimate and avoid chargebacks. They can have up to one month to review the order before the authorisation expires, depending on the PSP they partner with. Customers see this as a “pending” payment in their bank account until the merchant approves it.

Capture, on the other hand, means that the payment can be transferred immediately and doesn’t have to go through the merchant for review after it was authorised. This is the most common option and takes only a few seconds.

Payment Service Providers are responsible for authorising a payment


From then on, it is quite simple. The Issuing Bank charges the cardholder and the payment is processed via a card network (Visa, MasterCard, American Express) until it reaches the Acquiring bank (merchant’s bank), who settles the payment and deposits the funds in the merchant’s bank account. Overall, the PSP’s job is to facilitate the movement of funds and ensures that the payment arrives in the account.

Connecting with the right PSPs and deploying payment technologies can be a stressful, expensive and time-consuming process. At Imburse, we understand the power that payments have in your business. Our mission is not only to connect companies with any PSP and technologies available on the market, but to do so easily, quickly and inexpensively.

If you have any questions regarding PSPs or would like to know more about Imburse, get in contact with us today via the button below.


Mariana Marques

Mariana is a content writer at Imburse, specialising in Finance and Technology topics.

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