It claims to be the first bank in the UK to use blockchain in this way, trialling it in an iPhone app used by staff that reduces the time it takes to transfer cash by days, and has ambitions to expand it further in the future.
The blockchain experiment was spurred by the bank's investment in Ripple, a Silicon Valley-based startup working on how blockchain's digital ledger technology can be used in finance, via its Santander Innoventures VC fund.
"The need for finance has evolved from providing a physical pound in your pocket or card in your purse, where you pay at a till, to being seamlessly integrated into a new, always on, connected lifestyle," said the bank's head of customer and innovation Sigga Sigurdardottir.
“At Santander we work hard to ensure our banking is simple, personal and fair and believe new blockchain technology will play a transformational role in the way we achieve our goals and better serve our customers, adding value by creating more choice and convenience.”
Several banks and financial institutions are experimenting with blockchain, which acts as a digital ledger for transactions and processes.
Barclays has tested out derivatives trading using blockchain while it has also supported startup Circle in its money transfer app which uses blockchain technology.
Both Barclays and Santander are members of the R3 consortium along with several of th world's biggest banks and finance firms, including Goldman Sachs, HSBC, JP Morgan and Credit Suisse. The group is working on implementing standards for blockchain use to ensure it works across services.