<a href="https://www.merchantconnect.com/CWRWeb/glossary.do?glossaryLetter=i#14" rel="nofollow">https://www.merchantconnect.com/CWRWeb/glossary.do?glossaryL...</a><p>Visa and Mastercard are the usual parties when it comes to giving out merchant accounts. An ISO is an institution created by a bank or a consortium of banks to allow merchants to accept various cards, but without having a merchant account with either Visa or Mastercard, instead they have their merchant account with the ISO or 'MSP' as it is also called.<p><a href="http://www.mastercard.com/au/merchant/en/acquirers/communications/msp_rules.html" rel="nofollow">http://www.mastercard.com/au/merchant/en/acquirers/communica...</a><p>It is unlikely that you will find yourself in the position of a MSP or that you will be dealing with one, banks normally use these only for groups of merchants for which it makes no sense to have a direct merchant account with the large card companies.<p>They are an instrument for 'vertical' markets. An example of a member service provider is for instance PaySquare, positioned to accept point-of-sale transactions.<p><a href="https://www.paysquare-services.eu/form.aspx?id=71&#38;ver=4&#38;lang=en-EN" rel="nofollow">https://www.paysquare-services.eu/form.aspx?id=71&#38;ver=4&...</a>