Just wanted to relate something that happened this weekend. When I opened a CCB bank account almost 4 years ago, I used my US passport and a mainland phone number. Somewhere in 2018, I no longer had that phone number since it was company supplied. My bank account was still working, but I'd get a message every time using the ATM telling me to that my phone number was no longer valid. I could still use the ATM to deposit money and had no impact using the bank card or my connected WeChat wallet.

This weekend, I went to the CCB branch to change my number as I'd gotten a new number a few weeks before. I wanted to set up Alipay, and in order to complete registration, Alipay wanted to verify the phone number with the one registered with the bank.

The change was successful, but I had to provide more information than when I opened the bank account. Specifically, they wanted my SSN (US federal tax id) and home address. I presume there is some requirement to now start reporting back to the US. They did not care about having my residence registration papers, although they did put ask for the hotel that I register with. They were also a little picky about my signature, as first I signed like I would back home as barely legible cursive. They wanted me to sign neatly, as in block letters as Last Name, First Name, Middle Name, like on my passport.