Yes and No. The number of payment processors a merchant may have is controlled by its payment gateway service provider. For example, if a payment gateway only works with the American Express payment processor , then the merchant only can accept payments from Amex, therefore customers who use other credit card brands wouldn’t be able to use their cards on this merchant’s website.
Therefore, merchants should use a payment gateway like Octalas to help diversify their payment options and enable the acceptance of multiple popular payment processors such as Visa, MasterCard, American Express, JCB, Discover, SEPA Transfer, and many types of cryptocurrencies.