Note Merchant Pay Limits — Big Purchases Need Card Backup

Note Merchant Pay Limits sounds like a micro-optimization until you are in a Jinjiang apartment where the dehumidifier runs like a second roommate.

A friend visiting from Shanghai who thought Chengdu was 'mild' once forgot to screenshot the QR code and became that person at the gate. The fix took less time than telling the story.

Try this once: write the rule on your phone lock screen for three days. If it survives, it is yours.

Works for me in Chengdu humidity.