1. Confirm whether the merchant supports pos payment: When shopping, customers should first confirm whether the merchant supports pos payment to avoid unnecessary troubles.

2. Know the credit card limit: Cardholders should know the credit card limit and check the available balance of the account before use to ensure the smooth payment of customers.

3. Protect personal privacy: Cardholders should pay attention to protecting personal information security when using pos machines to swipe their cards, such as avoiding leaving sensitive information such as credit++and passwords in public places.