SCA stands for Strong Customer Authentication, and is an EU requirement for online payments. All payments where payment cards are used are covered by SCA, here the customer is introduced to two-factor authentication. This includes two of the three forms of verification from the customer, it can be something the customer knows e.g. a password, something the customer has e.g. a mobile or something the customer is e.g. facial recognition. The two forms of verification used must be independent of each other. SCA is used when setting up a subscription, if you want to save your card details on a site, or you purchase for over 225 DKK/30 euro.