My sister borrowed money from his house and asked if my family had a room card. My sister asked me to provide a second residence certificate. Does it affect me?

Is that your sister? Sister? There is basically no problem. Just a proof. If something really goes wrong, just say you don't know. Your sister took it by herself, without your permission. It won't be a problem.

Banks need to see the second residence certificate, mainly because when the mortgaged property right is the mortgagor's only house and it is less than or equal to the most basic local housing area standard, even if there are legal disputes such as overdue, the auction is not allowed. At this time, if the mortgagor has a second house, the bank can handle the mortgaged property.