On WeChat Pay 微信支付 and Alipay 支付宝, 支付码 is the QR/barcode the customer shows for the cashier to scan. The reverse, the merchant’s static QR you scan, is called 收款码 "receive-payment code."
mistakes
Don’t confuse 支付码 "code I show to pay" with 收款码 "code I show to be paid." The same store wall might display both: the merchant’s 收款码 for customers to scan, and the customer’s 支付码 on phone.
