Based in Boston, Santander is a large multinational bank and a member of the Spanish Santander Group. It mainly operates as a retail and commercial bank. Instead of operating as an acquiring bank, it routes all merchant services through partners in every country. In the US, Santander has its own online payment gateway solutions and security and partners with First Data for merchant services.
In the UK, it operates differently because it is a separate company. Based in London, the UK company was founded in 2010 after the Santander Group acquired Abbey National, Bradford & Bingley, and Alliance and Leicester banks.
Though one of the larger banks in the UK, it does not provide any merchant services. Instead, these services are offered through its partners, Elavon and iZettle.