What does it mean to receive SMS debit card income 1 yuan?

I received one yuan, which is the interest generated by the money in my personal account.

This business is called balance change reminder in banks. Different banks may have different names, but they are all the same. Specifically, if you open this service for a card, there will be an agreement record in the back-end database of the bank. When you deposit and withdraw money through ATM, or use your card to spend money on POS, or just use your card number to spend money online, the transaction will be sent to the host computer of the bank for specific processing, such as finding your card in the database and modifying the balance. At this time, if this card is found to have this short message protocol, the transaction information will be generated in the reserved format and sent to your registered mobile phone through the interface provided by the operator.