Yes In the process of handling credit cards, banks usually require to fill in the phone number of their spouses as contact information. This is to be able to contact family members when necessary, such as during the examination and approval process or when it is necessary to verify identity in case of emergency. The husband didn't fill in the phone number when he applied for a credit card, so the bank wouldn't contact him. However, if the option of requiring a guarantor is selected when filling out the application form, the bank will contact as a guarantor.