For the direct merchants of UnionPay, the process is as follows:

1. Card swiping information (including tracks and passwords) is accepted by POS machines and sent to the acquiring system of UnionPay through acquiring institutions.

2. The UnionPay acquiring system sends the message to the issuing bank of the credit card through the UnionPay core exchange platform, and deducts the money from the corresponding card account of the issuing bank according to the transaction instruction.

3. after receiving the successful deduction, unionpay core exchange system will return the transaction result to the POS terminal.

4. At 11 o'clock that evening, the liquidation information began to be processed in batches.

on may 5th and t+1st, all banks will transfer funds from their position accounts in the People's Bank of China according to the liquidation documents (instructions) of UnionPay, that is, the transaction funds will be transferred from the credit card issuing bank to the merchant's acquiring bank.

6. The acquiring bank will transfer the funds to the specific clearing account of the merchant (or directly by UnionPay).

as far as the roles are concerned, there are cardholders, merchants, acquiring institutions (banks or institutions that provide services for merchants), transfer clearing institutions (card organizations such as UnionPay and VISA) and card issuing institutions (credit card banks).