For example: the applicant's age, education, household registration, work, social security payment record, marital status, housing situation, personal credit record, personal assets (time deposit certificate, wealth management products, etc. ), etc.
Stable working income and good credit are more important factors.
In short, the bank will check the credit limit according to the personal credit situation. There are thousands of lines.
The credit limit will not be fixed. After the personal credit situation improves, the bank will also take the initiative to increase the credit line for you.