It’s okay! If it is a domestic card, it will be fine if you wipe it clean and re-write it. Because domestic cards are generally used for secret payments, sometimes the signature is not even read, even if the password is correct. If it is a foreign card, a signature is usually required. If the signature is incorrect, payment will not be made. When I went to a casino in Macau, I experienced that the card was swiped, the signature was wrong, and payment was not given. It’s okay in China, please feel free to use it!