Banco Santander has partnered with blockchain startup Vottun to develop a blockchain digital payment system for Madrid, Spain's public transport. Customers will be able to download an app that will validate their information on a blockchain for bus companies, taxis, bicycle hires, motorcycles, metro and car rentals with a single onboarding and payment system, according to a report by Yahoo Finance.

"The onboarding and validation process of user information with be the same for all the mobility services offered in Madrid through the EMT app," Rohan Hall, CEO of Vottun, said in the report. "This will make it easier for citizens to use public transportation, and to pay in an easier and more transparent way."

This partnership is part of a larger initiative called Madrid in Motion by the Municipal Transport Company of Madrid, which aims to streamline the city's public transportation system.