There is no handling fee for using credit cards for WeChat payment transactions. The method of WeChat binding credit card is as follows:

1. Find the "wallet" option in the WeChat my interface and click Open.

2. Find the "Bank Card" option in the wallet interface and click Open.

3. Click the "Add Bank Card" option at the bottom of the bank card interface.

4. Enter the WeChat payment password to verify your identity.

5. Enter the cardholder's name and card number in the Add Bank Card interface, and click Next.

6. Enter the mobile phone number bound by the bank card, and click Next.

7. Fill in the received verification code and complete the binding.