1. Credit score: Banks usually check the applicant's credit score when approving mortgage loans. If the applicant's credit score is low, it may be considered as high credit risk, resulting in the rejection of the mortgage application.

2. Credit card overdraft: If the applicant's credit card is overdrawn, the bank may think that his financial situation is unstable, which will affect the success rate of mortgage application.

3. Credit records: Banks will also pay attention to the applicant's credit records, including overdue records and default records. If the applicant has a bad credit record in the past, the bank may have reservations about his mortgage application.

To sum up, the use and repayment of credit cards have an important impact on mortgage applications. Through good credit score, no overdraft and good credit record, the possibility of successful mortgage application can be improved.

Extended data:

According to China's financial supervision policy, banks will comprehensively consider the applicant's personal credit when approving loans. The credit scoring system is jointly issued by the People's Bank of China and the State Administration of Foreign Exchange, and is used to evaluate personal credit risk. As a common credit tool, the use and repayment of credit card can reflect the repayment ability and credit record of the applicant, thus affecting the mortgage application. Therefore, before applying for a mortgage, it is recommended to use the credit card reasonably, repay the loan on time and maintain a good credit record.

Summary:

Failure to apply for a mortgage may be related to credit cards. The bank will pay attention to the applicant's credit score, credit card overdraft and credit history. Good credit score, no overdraft and good credit record are helpful to improve the success rate of mortgage application.

The above answers are based on China's financial supervision policies and common approval practices.